Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: EL34 on October 04, 2012, 01:31:12 pm
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After several people asked if I would make a turret board for relays, I drew up a design and cut out a few on my CNC machine
I think having turret lugs for the relay socket is not that great of an idea, but for the wires, it's great
So, I made some hybrid prototypes just to nail down a design
Andy at Mojo drew up the final designs
I am getting some laser cut samples to approve and then they go into production.
The final boards will look more like the green bias checker board shown below in the before and after image.
The final design on the relay board will be for a single relay, not a double as most of my prototype board pictures below show.
There's a close up shot of one of my crude prototype relay boards shown below
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Great idea EL, I was thinking that if you solded the relay to the top of the turrets it would make it difficult to remove if there was a problem with it later. I have sorced some 12v relays but the pins don't fit into the IC socket.Thanks
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Yes, I think that will get it done. They look good.
Maybe a couple of weeks and you'll have all the new parts in stock?
Brad :icon_biggrin:
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Very nice idea, simply and effective
K
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I think that is a VERY well thought out design & I like it!!
I agree with you that the turrets are more useful for the wiring but not as useful for the relay socket.
GREAT design! THANKS!
Doing it that way would save ALOT of time compared to lacing turrets together. Really ingenius approach, IMO.
Tubenit
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Yes, I think that will get it done. They look good.
Maybe a couple of weeks and you'll have all the new parts in stock?
I already have all the parts in stock.
All I need to do is figure out what to sell the boards for.
It takes 7+ minutes to cut one board out on the cnc machine and I usually charge $1 per minute for machine time.
But I cut out many at a time on a bigger sheet and so that reduces cost
Once the machine is set up, it can cut out as many as I want.
What do you guys think the board itself should sell for?
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I look at it this way ..............
IF I bought the board material & cut the board with my hacksaw (which is what I use) & drilled my own holes & laced my own turrets ...... to get two relay layout on one board done would probably take me 45 min at least.
Since these don't have to be laced and they are predrilled (correctly vs. my hand held drill), that would be a huge time saver for me. Plus this is a very good design.
I am thinking maybe $7-10 for the drilled board that fits two relays? Of course, the relay sockets, turrets, etc...... would be a separate and additional cost. I don't know if that would be cost effective for Doug, but that would be what I would think might be a reasonable range?
Anyhow, they would easily be worth that to me so I didn't have to cut, drill and lace my own.
The other advantage of Doug's is that the one I built had the relay socket into turrets. Do-able but somewhat challenging to solder. And it made the installed relay set somewhat higher than I would like. This would allow a lower mounted relay which is an advantage placed between the layout board and the pots.
With respect, Tubenit
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I was also thinking in the $10 range. I've always wanted to experiment with relays, and this looks like a solid design......I'd buy one
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I'm thinking $7 on the 12 boards that I cut out for this test run.
The design looks very good to me and so what may happen next is I have the boards made at an outside source
Just like I did with the bias checker boards.
The bias checker boards were originally made on my CNC, then outsourced
The quality was much better and the price came way down.
Here's a shot of a bias checker board before and after
The off site made boards are way nicer
Plus, the off site boards can have silk screening with text
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And now that I look at this board with all the parts on it. I can get rid of the 4 lugs with red squares.
The relay coil + and - wires can just be attached to the diode lugs
Now it's down to 16 turret lugs
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No reason the diode needs to take-up turret space. Boff two more small holes on the 0.3" spacing of the DIP relay and stuff it in there.
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If you're going to lose those four turrets, I would lean more towards PRR's way. I think that's reasonable & still allows for turrets that you can drop wires into instead of wrapping around.
The reason for that is most of the relays are in a somewhat narrow space between a layout board and the pots. Yes, one can wrap wire around a turret. However, on the pot side of the relay, that is somewhat challenging because of the chassis front and pots there.
In that narrow space being able to drop a wire into a turret hole on top sure does simply things. I would suggest at least punching out the hole for those (4) turrets so they could be an option for those wanting them.
Just an opinion. I'm supportive of how ever you want to do this. All the options are workable, IMO.
With respect, Tubenit
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No reason the diode needs to take-up turret space. Boff two more small holes on the 0.3" spacing of the DIP relay and stuff it in there.
best plan....
for < 10 bux. i'd hit it.
--DL
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I misread Tubenit's post, but I'd wiggle the turret lugs to allow a tad more space.
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Boy, I would have loved this 6 months ago. I've since been making my own relay boards that look almost identical, only of course I use buss wire on the bottom to jump the eyelets/turrets. I'm still really excited by this thread because the boards are so time consuming, and a pain in the ass to wire.
My only suggestion would be to cut the board in half and sell individual boards or even a set of two if need be. That way, if you have to switch something early in the preamp and a master volume at the end of the preamp, you won't have to run their wiring needlessly close to each other, and can isolate the boards with some physical space. I'm sure the one board could be more useful to some, but it doesn't have the same flexibility.
But yeah, this is great idea since the only other relay PCB out there are crap or cost-prohibitive.
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Would there be any capacitive coupling/leakage with the traces being so close together?
Also will the farmed out boards be hole through, I think that's what they call it?
Brad :think1:
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Looking good EL, For all my builds i use a standard 2mm thick copper clad pcb sheet and use a standard type turret lug and these also are too long to swag so i leave a circle of copper around the lug (after etching)and just solder the lug in place,so is it cheeper to use off the shelf PCB board. Also if you are using an IC socket you have to solder it in place so the turrets could be as well. This is another option, don't drill any of the holes to cater for the turrets and drill all the holes the same size as the relay pins,that way rather than running a wire off the lug the wire can be soldered directly to the board and this will give options. Thanks :icon_biggrin:
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No reason the diode needs to take-up turret space. Boff two more small holes on the 0.3" spacing of the DIP relay and stuff it in there
That might work. Have to see if I can bend the diode leads over and fit between the lugs.
I could leave the four holes just in case someone wanted to add more lugs.
You still need to jumper the coil + together on each half
An under the board wire or wrap around a turret would method be good.
And you should jumper the coil + on each half, before you mounted it in the amp.
The big double line in the middle is where you can cut the board in half, but then you only have one mounting hole unless you waste the right half and cut the board further to the right
Would there be any capacitive coupling/leakage with the traces being so close together?
I can only guess, but I say no. Most relay boards have traces closer together than my boards do
Also will the farmed out boards be hole through, I think that's what they call it?
Probably, that's how the bias boards are. The solder pads go through both sides of the boards.
Looking good EL, For all my builds i use a standard 2mm thick copper clad pcb sheet and use a standard type turret lug and these also are too long to swag so i leave a circle of copper around the lug (after etching)and just solder the lug in place,so is it cheeper to use off the shelf PCB board. Also if you are using an IC socket you have to solder it in place so the turrets could be as well. This is another option, don't drill any of the holes to cater for the turrets and drill all the holes the same size as the relay pins,that way rather than running a wire off the lug the wire can be soldered directly to the board and this will give options. Thanks
I will be using off the shelf .062 inch thick boards and off the shelf turret lugs made for .062" thick board.
Most people don't want to solder to PC board traces. As Jeff pointed out above, it's really tight working in the amp. The best way is to drop a wire down a turret hole and solder it from above.
If I have these boards made, you can always just solder right to the solder pads where the lugs would normally go.
The manufactured boards would have through hole solder pads on both sides of the boards on the lug holes
I will not be assembling these boards, so you can build yours any way you want it.
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EL34,
I just want to say THANKS for your help with this! I am impressed with your willingness to continue helping this amp community. Bravo!
When I look at the unmatched quality of your business service, fast shipping, top notch parts, Library of Information (something I continue to refer to), your posts, sponsoring this forum, actually being a great guitarist yourself, instructions on recording music, and appropriately warped sense of humor .............
I am genuinely grateful for ALL you do to help this amp building community get great tone!
I think these relay boards will be a huge help for those of us that like relay switching.
With the original relay documentation and instruction you gave us ........... & these recent threads, schematics and layout ............. installing relays is a very do-able enterprise and a really fun feature to have.
Even playing here at home, I almost always have the ft switched relay pedal hooked up with the D'Mars OD Special. The ft switched relays sure give one a bunch of tonal options on the fly.
THANKS & with respect, Tubenit
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Thanks,
It's fun for me to design things
Ok, going with PRR's idea, here's a doctored image with 4 turret lugs removed and the diodes are in regular pc pin sized holes
Crap, I just noticed that I have my relay coil Plus and minus reversed
Working with the copper side upside down confused me I guess
Ok, I assembled another one with the correct + and - indicated
I just soldered the diodes into the existing turret lug holes
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What I like most about this is it suggests a good general strategy for getting components that would be awkward in a turret board layout well integrated into a turret board design.
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Yeah, the mix of pc board holes for the sockets, diodes and turret lugs looks like the way to go.
I know that I hate soldering wires to pc boards
I much prefer Turret lugs
I updated the hookup info on my relay page in the library.
http://www.el34world.com/projects/relay_switch.htm (http://www.el34world.com/projects/relay_switch.htm)
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Again a great idea, Two things, are you still using the IC socket to mount the relays?? If so, how snugg/tight are the sockets to be able to hold the relay if the chassis is mounted upside down,could the relay work itself loose :think1:. This was mention to me when trying to find a socket for the larger relay pins that are on the 12v relays that i have( i did find a socket that will fit) but i was corcerned that the weight of the relay might work itself loose. It was suggested that a wire retainer like used on tubes or a light guage insulated wire tied around the relay, zip tie. :dontknow: Thanks
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Something like this ?
(http://epub1.rockwellautomation.com/images/web-proof-large/GL/1040095.jpg)
http://www.ab.com/en/epub/catalogs/12768/229240/229266/229655/229727/tab4.html (http://www.ab.com/en/epub/catalogs/12768/229240/229266/229655/229727/tab4.html)
(http://www.schukat.com/schukat/catalog_en.nsf/lookupfiguresweb/E6481|a|F95132|f|a|w/$file/wi.jpg)
http://www.schukat.com/schukat/schukat_cms_en.nsf/index/CMSDF15D356B046D53BC1256D550038A9E0?OpenDocument&wg=E6481&refDoc=CMS11515ED0477BF2C3C12578F7003F0082 (http://www.schukat.com/schukat/schukat_cms_en.nsf/index/CMSDF15D356B046D53BC1256D550038A9E0?OpenDocument&wg=E6481&refDoc=CMS11515ED0477BF2C3C12578F7003F0082)
K
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Timbo, the relays that I got from Doug are no way, no how coming out of that socket without some careful plier work. :smiley:
Doug, nice work on the relay board. Myself, I'll gladly cough up 10 bucks to not make my own!
Tubenit, once again you are part of a Very Good Idea. Cheers!
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Yeah K, Something like the bottom one. :icon_biggrin:
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Again a great idea, Two things, are you still using the IC socket to mount the relays?? If so, how snugg/tight are the sockets to be able to hold the relay if the chassis is mounted upside down,could the relay work itself loose :think1:. This was mention to me when trying to find a socket for the larger relay pins that are on the 12v relays that i have( i did find a socket that will fit) but i was corcerned that the weight of the relay might work itself loose. It was suggested that a wire retainer like used on tubes or a light guage insulated wire tied around the relay, zip tie. :dontknow: Thanks
The relays are in the sockets very firmly
You can't easily pull the relays out of the sockets with your fingers.
The only way is to stick a very thin flat tool under the relay and pry it out gently
You don't need any wire retainers
These are very light weight relays
If you had a very heavy relay, I can see the need to strap it down
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two 1/8' holes on each end of the relay socket is you need. use a 1/8" zip tie.
--DL
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There's already mounting screws at each end
If you must be anal, you can rig a wire with round terminal lugs and use the mounting screws
really, this is not an issue, you guys are dreaming up scenarios that can't come true
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Thanks EL, The socket is a great idea, and not using your parts, i found that there is not a IC socket that fits my relays tightly but the socket that K has presented is only a couple of bucks each.Thanks again :icon_biggrin:
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Thanks EL, The socket is a great idea, and not using your parts, i found that there is not a IC socket that fits my relays tightly but the socket that K has presented is only a couple of bucks each.Thanks again :icon_biggrin:
The 5volt low signal relays I stock are also available in 12v
It may be worth switching
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really, this is not an issue, you guys are dreaming up scenarios that can't come true
You mean like they do with the federal budget? :l2:
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I can't imagine the relays coming out of the sockets? They fit pretty tight, IMO.
I broke one (out of 4) trying to get it out. How's that for a tight fit? I couldn't budge it with my fingers and using pliars to wobble it loose, broke a side. I had to order a replacement from Doug.
Just saying. with respect, Tubenit
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Very nice.
How about a board without the turrets and make those holes a bit smaller?
I can see the turrets very useful for prototype work but for final assembly, I would rather just wire direct to the board.
Thanks!
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I am not including the turrets
You would order all the parts separately to make the board yourself
Just solder to the turret pads
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Ok now we have a double any chance to make a single board also. I have been building my own for a while but my time is just worth to much to me right now.
I just dont mind buying them instead. I work to much anymore its taken me 3 months to to get my board done for the new TOS Im building.
Building planes is cool but the company I work for thinks I belong to them 24/7 ( LOL).
Doug keep us posted, Im in for a couple when you get them done .
Thanks Bill
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Well, I have 10 of them right now if anyone wants them.
I'll do the boards for $7.50 each with all the lugs installed
By boards, I mean just the boards
To complete the boards you also need
2 - relay sockets
2 - relays
2 - 6-32 x 1/2" long screws
2 - 1/4" nylon standoffs - use #8's for now, I am ordering #6 standoffs
Several of the boards already have the lugs and sockets attached
But I think I will go ahead and do that to all 10 boards
Let me know if you want one
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Please set aside 2 of those boards for me! I've got some other stuff to order from you & I'll place an order for all of it before this week is up.
I am not sure if I'm understanding you correctly? IF you are adding the turrets and the socket relay, I'd prefer you charge me $7.50 a board to help compensate your efforts.
THANKS, Tubenit
FYI: Just a reminder ................. there is a thread here that has some good documentation plus it contains the link to Doug's Library of Information on building these relays:
http://www.el34world.com/Forum/index.php?topic=14348.0 (http://www.el34world.com/Forum/index.php?topic=14348.0)
There is enough information to make this a reasonably easy project & I will tell you that it's great being able to switch tones with foot switch.
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EL34,
PLEASE don't throw any sharp or heavy objects at my head ..................................
Any chance that you'd be willing to carry a relay power supply board also ??? Since this would be all turrets, the normal board material could be used.
I built mine with an extra 330uf cap that was probably not needed at all?
I'm thinking that "option 1" would be the best since it would maintain the narrow width that the relay boards had?
In the attached photo, the relay power board I built works fine with the D'Mars ODS but would be too wide to use in my Tweed BluezMeister that has a narrower "tweed style 18w chassis".
AND if you're not interested in carrying a relay power board punched out with turret holes, we can easily build our own.
With respect, Tubenit
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Ok, I forgot about the lugs and labor, $7.50 works better
I'll change my post above
When I get to the shop, I will create a public parts list for all the parts.
That way, people can click one button and add all the parts to the shopping cart.
I'll be doing a power supply board also when I get time.
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Option 1 looks the best
You only need four turrent lugs
The voltage regulator, capacitor and bridge can go into pc sized holes
The bridge can go also have four lugs
2 for AC in wires and 2 for DC out wires
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Option 1 looks the best
You only need four turrent lugs
The voltage regulator, capacitor and bridge can go into pc sized holes
The bridge can go also have four lugs
2 for AC in wires and 2 for DC out wires
So, I'm thinking from this response that you're envisioning using the copper boards instead of the "normal" layout board material?
I was thinking the normal board material but have no strong preference ? I'm not sure exactly what you have in mind on this?
With respect, Tubenit
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The relay board and the power supply board would be .062" thick pc boards just like the bias boards shown below.
I am working with Andy at Mojo on them because he has a good boardmaker.
Andy makes the Hoffman bias boards and sells them with my name on them
The finished relay boards and power supply boards would look like the green boards in the image down below
See how all the holes have solder pads on both sides of the boards?
I changed my mind on option 1
Here's a quick mock up of the power supply board
The bridge could be substituted with 4 stand alone diodes
The green lines would be under the board traces
I just grabbed a piece of board and drilled some holes for this mock up, it's not a real board
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Doug your price is really competitive
Here (http://grangeramp.com/shop/index.php?main_page=product_info&cPath=37&products_id=53) is a commercial product similar to your proposal
(http://grangeramp.com/shop/images/3_relay_switching_board_full.jpg)
yes, it has a good look, but your's is only a prototype
Your PS is way long better, the connection is by turrets and comparing prices you won of many lengths !
K
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Well that board in the picture above has all the parts
Mine will be just the board and then you have to buy the parts
So with the parts, my boards would cost you more than $7.50
Yes, I do not want to put the power supply on the same board as the relays.
I like to have the power supply down near the power tranny and then just run 5VDC to the relay boards
And I don't like to have AC coming up near the pots and signal wires
My relay boards will probably end up under the pots near signal wires
Also, you can hook up more than one relay board to the power supply, so it does not make sense to me to have the power supply fixed to a relay board
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I agree with Doug, I don't want the relay power amps on the same board as the relays. I want options to move it where it will be it's quietest.
With respect, Tubenit
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Of course your price refers to only one board, I considered it
your realization is way more strong than that and your PS is better for many reasons, not the last the fact that you can keep the AC path far from the relays and sensitive circuits
K
p.s.: I posted at the same time with Jeff
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What do you think about the mock up power supply
It's only 1.5" x 2" which means that it can fit on the sides of an amp chassis
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I like the idea of mount the PS on the sides of the amp,the smaller it is the easy is to mount it also if there is low room
if I can say something I would like to see two holes as to be used for a radial capacitor in substitution of the axial capacitor (only if required) and a place to connect a small capacitor in parallel with the output (near the 7805)
K
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You mean like this?
Axial or radial for the big cap
Optional radial for the output cap
The holes and traces would be there for all those choices
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Yes that was what I was thinking
K
p.s.: may be you can move the optional cap holes more near to the regulator, so you can mount it also if an axial principal cap is mounted
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PSU board looks great. Agree, smart to keep PSU and relay boards separate to keep ac by the PT and power cord/switch/fuse.
I like the radials they have now, size, spec. and price wise. ($0.02, drop the big axial cap option and shrink the PSU board a little more.)
Brad :thumbsup:
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Just re-stocked the bin full of 4700uf/16v caps, so I would like to use them up
The board is only 2 inches long, which is tiny
And it's only 1.5" tall which will fit on the sides of Fender chassis
I don't really think a cap on the output is needed, but the option is there
A radial is the only thing that would fit on the tiny layout.
If you really want to use an axial on the output you can stack it on top of the big axial.
Here's what Andy at Mojo drew up
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Just re-stocked the bin full of 4700uf/16v caps, so I would like to use them up
The board is only 2 inches long, which is tiny
And it's only 1.5" tall which will fit on the sides of Fender chassis
Understood and agree, it's plenty small as is.
Andys drawing looks good too. Still think the relay boards should be singles, but you can have them made where they score them so they are doubles that break apart into singles.
Brad :icon_biggrin:
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Andy just emailed me
You got your wish
He has to make them as singles for some of his amps he makes
And he gets a better price break on singles because the quantity would be higher
It does make more sense to have singles
4 relays in an amp like on the D'mars are not that common
He also figured out a way to get the optional cap on the same board even if you use an axial for the main cap
He is mailing me a couple laser cut test pieces so I can make sure all the parts I stock fit properly
I will probably go ahead and stock both the radial caps, besides the axial I already stock
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Very nice Doug!
Looking forward to buying a few for a new build to try them out.
Brad :icon_biggrin:
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Anyway you could make these into two individual units?
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Doug do you have any of the doubles left if Im not mistaken 1 page back you said something like you had 7 left and i think you mentioned a price I would take 5 right know if you have them .
once you have the details worked out and in stock I look forward to some singles and power boards.
Thanks Bill
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Anyway you could make these into two individual units?
Huh? Read the _WHOLE_ post. :icon_biggrin:
The PSU board will be 1 individual unit and the relay board will be 1 individual board per relay.
Brad :icon_biggrin:
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Not talking about the relay power supply. Talking about the relays themselves.
Every pic I've seen shows two relays on one board together. I have needs for two
relays in two separate places. One relay in the preamp one by the power amp.
Anyway you could make these into two individual units?
Huh? Read the _WHOLE_ post. :icon_biggrin:
The PSU board will be 1 individual unit and the relay board will be 1 individual board per relay.
Brad :icon_biggrin:
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Andy just emailed me
You got your wish
He has to make them as singles for some of his amps he makes
And he gets a better price break on singles because the quantity would be higher
But you're right, everywhere else they were talking about the double relay board. And I was thinking "gee, I wish they'd make them as singles" :laugh:
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The relay boards will be singles.
I have 8 of the doubles left
Jeff is the only one that spoke up for two of them
Just add a note to your order that you want a double relay board
The sample laser cut boards from Mojo should be here today for me to ok
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Every pic I've seen shows two relays on one board together.
Sorry Dave, yes your right all the pics show doubles.
But things changed later as the guys pointed out.
Brad :icon_biggrin:
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I got the laser cut boards from Andy at Mojo today
The boards are cut to make sure all the parts fit as I designed them to
He just uses some black board material, it's not pc board material
There's a couple things I need him to correct and then we are good to go.
The relay board was only .75 inches wide.
It was supposed to be .9 inches wide so that you had room enough to wrap wires around the turret lugs.
So I am having him re-do the width on the relay board to .9 inches
I am having him move the Ac lugs on the power supply board farther away from the bridge
One lug is really close to one of the Ac holes
Here's a shot with the laser cut boards and parts added
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Here's Andy's updated drawing after fixing a few things
He re-did the bridge area so that you can use stand alone diodes or a BR305 bridge
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To me, it looks like there is only enough room to wrap wire on the top row on the relay board now, bottom row looks like same spacing as the test piece....
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Not sure what you are saying, here's shot of my prototype board
Plenty of room to wrap around the lugs
The production boards will have the same spacing as my prototype board
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Sorry, I was looking at Andy's drawing and sample boards, not your prototype. It looks like the top row of turrets have more space than the bottom row. Looking at your prototype, maybe that is intended. Sorry for being confusing. :BangHead:
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If you mean Andy's black boards shown a couple post up, the text below those boards explains that he made the relay board too thin at .75 inches
It was supposed to be .9 inches, just like my prototype
That has been fixed
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I have continued to update the ARCHIVES information on relay switching. Doug's new relays should work perfect for this.
I've included some new photos & illustrations in an effort to make this even easier those who wish to try it.
http://www.el34world.com/Forum/index.php?topic=14348.0 (http://www.el34world.com/Forum/index.php?topic=14348.0)
With respect, Tubenit
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Thanks for all the info updates Jeff
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Guys,
I got two of Doug's prototype relay boards. Man, these are VERY nice boards! Very neat layout and very very compact.
More impressive in person than in the photo that Doug posted. These will be very easy to place between pots and turret board and
super easy to solder wires into.
Nice job, Doug!! I like these quite a bit better than the ones I built for myself.
With respect, Tubenit
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Thanks
Those are my homebrew CNC prototypes
There won't be any more of those
But, the production ones will be even nicer because they will have through hole solder pads on both sides of the board
The same with the relay power supply boards.
You got two of the 10 boards I made
Another customer bought the other 8 of them
So they are all gone until the production boards get here which should be 2-3 weeks from now
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I think these are probably compact & narrow enough to work well with a Tweed style chassis which is what I plan on using a pair for. So, I'll give an update hopefully within the next two weeks on how well that works out.
Tubenit
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ok thanks
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Looking forward to buying some of these relay boards for many projects, Thanks.
Mark
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OK, I installed two of the relay boards into my Tweed BluezMeister amp.
Now, the TBM is in a 18.5" X 6.5" X 2.5" 18 watt style open end chassis. I actually cut the 20" length down to 18.5"
This amp combo is about the size of a 5E3 combo amp.
However, it has clean/OD, PAB, & midboost. The clean/OD and midboost are relay switched using a foot switch box.
It also has on board an active FX loop. I left out the LNFB around the 2nd triode and I changed some of the component values.
What I am trying to do is convey that I have ALOT going on in a very small chassis ............ AND the relay boards are super quiet.
They were very very easy to wire up and I actually built a relay power supply board that I mounted on L brackets on the side of the amp.
The combo amp is so quiet at idle that I can almost not hear it & yet when I hit a chord, it's VERY LOUD with 6L6's in it.
I think it would be easy to walk into a room with the amp on and perhaps not hear it at all with it on either clean or OD? This is maybe the most quiet combo amp I've owned. It is actually quieter than the D'Mars ODS which has surprised me.
I might add that the previous W____r relay board left me with some hum on the clean channel. Hoffman's relay boards (2 of them) seem to be quieter than the previous 1 relay board. Perhaps I did a better job wiring up the amp??? However, I added an entire FX loop section so the amp chassis is even more crowded with wiring and still quieter than it was.
Very big thumbs up on Doug's relay boards!!!!! :thumbsup: :thumbsup: :thumbsup: :thumbsup: :thumbsup:
With respect, Tubenit
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Thanks Jeff
I'll keep you guys posted when they arrive here
Hopefully by the end of this month
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I was looking at your pic of the relay power supply. So you leave your relay power supply floating not grounding it to the chassis?
EL34,
PLEASE don't throw any sharp or heavy objects at my head ..................................
Any chance that you'd be willing to carry a relay power supply board also ??? Since this would be all turrets, the normal board material could be used.
I built mine with an extra 330uf cap that was probably not needed at all?
I'm thinking that "option 1" would be the best since it would maintain the narrow width that the relay boards had?
In the attached photo, the relay power board I built works fine with the D'Mars ODS but would be too wide to use in my Tweed BluezMeister that has a narrower "tweed style 18w chassis".
AND if you're not interested in carrying a relay power board punched out with turret holes, we can easily build our own.
With respect, Tubenit
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The relay power supply does not use the chassis as the DC ground
It is creating a 5 volt DC supply only for the relay coils
You can think of the 5 volt supply as if it were a separate 5 volt DC battery
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Thanks for the clarification EL34 the reason I asked is because I'm having grounding problems on one of my builds. If I'm not touching the strings this amp has a very audible buzz also shocks me when singing through a mic. I've check and check for a ground loop but I can't find it. I've re-grounded everything twice so far so the hunt is on...
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Every guitar and amp I ever played through buzzed (with the guitars volume up) when not touching the strings.
Guitars run a wire to the bridge so it's in contact with the strings, which runs back the the amps ground through the guitar cords shield. IIRC it's the players body capacitance that stops the buzz?
As far as getting a shock when playing and touching a mic somethings not grounded correctly. Do both the guitar amp and mic amp have a 3 wire power cord with the 3'rd wire (safety ground) conected to the chassis?
I've kissed a few mics while singing on stage and it's no fun. :cussing:
Brad :laugh:
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> audible buzz also shocks me
Input jack MUST connect (usually through chassis) to Wall-plug ground pin.
Somehow it isn't.
> the players body capacitance that stops the buzz?
The player, standing in a room not connected to anything, picks-up a buzz from all the power-wiring in the room. This CAUSES the buzz. When player is connected (through finger-touch) to the same ground as the amplifier input, buzz is much-much less.
It might also help to line guitar wire pot switch jack cavities with metal foil tied to jack ground, ground all non-live metal parts, and use shielded wire for anything more than an inch or so long.
You can't block ALL buzz. The pickup coils must "see" the strings through the poles, and most easy electrostatic shields will muffle the string tone.
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The player, standing in a room not connected to anything, picks-up a buzz from all the power-wiring in the room. This CAUSES the buzz. When player is connected (through finger-touch) to the same ground as the amplifier input, buzz is much-much less.
Ohhh. OK, thanks PRR.
Brad :icon_biggrin:
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I have a wall socket tester plug tests good. And the really strange thing is that if I touch the bass players bass while also touching my guitar I get a really loud buzz. I've built 5 amps and this is the only problem child.
> audible buzz also shocks me
Input jack MUST connect (usually through chassis) to Wall-plug ground pin.
Somehow it isn't.
> the players body capacitance that stops the buzz?
The player, standing in a room not connected to anything, picks-up a buzz from all the power-wiring in the room. This CAUSES the buzz. When player is connected (through finger-touch) to the same ground as the amplifier input, buzz is much-much less.
It might also help to line guitar wire pot switch jack cavities with metal foil tied to jack ground, ground all non-live metal parts, and use shielded wire for anything more than an inch or so long.
You can't block ALL buzz. The pickup coils must "see" the strings through the poles, and most easy electrostatic shields will muffle the string tone.
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Check for zero ohms resistance between amp chassis and round ground pin in the AC plug.
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Will do.
Check for zero ohms resistance between amp chassis and round ground pin in the AC plug.
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Steve what ohm rating would we be looking for I work on planes and when were are checking grounds were looking on a high rating for 500 milli ohms or .5ohms at the highest.
in more critical areas it's lower than that.
Thanks Bill
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> what ohm rating would we be looking for
For diverting buzz, many ohms can be acceptable. In the old hot-chassic days we sometimes used about 50K (at 60Hz) capacitive impedance (a compromise between buzz and shock).
A chassis ground SHOULD blow a fuse if the chassis gets straight 120V. This means 120V/20A or under 6 ohms.
Any decent wire and bolt should read well under 1 ohm, below the bottom of standard bench meters. Usually "it is or it isn't", meaning <1 ohm or just plain bad.
I think if the guitar-jack to wall-plug reads within a part-ohm of what the meter says with probes shorted, that's fine.
> I work on planes ...0.5ohms at the highest.
Planes may be more fussy; also planes are built with many sheets of Aluminum riveted together. Aluminum is prone to oxide (especially when flown in damp air) and not-great electrical contact.
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Well I finally found the source of the BUZZ!! I was playing the amp upside down and low and behold no BUZZ... I turn the amp over right side up and the buzz came back so I wiggled the power cord around and sure enogh the cord has a short right at the strain relief. The funny thing is that I tested the groung wire for continuity as well as resistance and both test were fine. Resistance between the plug tip and chassis ground point was 0.5 ohms but when the cord wiggled a certan way it was enough to break ground. Glad I have a 12' cord I got from Doug that I can spare a foot from... Thank you Sluckey and PRR for all the help!
Will do.
Check for zero ohms resistance between amp chassis and round ground pin in the AC plug.
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relay boards are here, see this post
http://www.el34world.com/Forum/index.php?topic=14598.new#new (http://www.el34world.com/Forum/index.php?topic=14598.new#new)
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Just ordered 4 single relay boards and 2 relay power boards + parts to mount/fill them.
Thanks Doug. :happy1:
Brad :icon_biggrin:
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I put in an order for 6 of each. Not sure how long he'll have these in stock. :icon_biggrin:
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Man, those look FANTASTIC!!!!! :thumbsup: :thumbsup: :thumbsup: :thumbsup: :thumbsup:
Super super nice design! I like 'em!
Can you please give the dimensions for the relay power supply board? Thanks!
With respect, Tubenit
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Thanks guys, I replied here in the new relay topic
Board sizes added to catalog descriptions
http://www.el34world.com/Forum/index.php?topic=14598.msg139084#msg139084 (http://www.el34world.com/Forum/index.php?topic=14598.msg139084#msg139084)
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Board sizes added to catalog descriptions
Sizes are excellent!
THANK you! With respect, Tubenit
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Just noticed something. :think1:
The boards each have a square through hole pad (or 2) on them. Is that for marking a ground connection?
Brad :icon_biggrin:
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Please use the new relay post at the top of the board for questions on the relay boards
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OK will do, sorry.
Brad :icon_biggrin: