Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: vitruv on December 02, 2018, 01:44:02 pm
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Dear all,
First thank you to all of you who continuously help the beginners !
I have a blues deluxe US (from 1995 I guess) and I use only the clean channel as a pedal plateform. Since the PCB starts to have some issues my best whish would be to reproduce the clean channel with the reverb (not the crunch channel) of the blues deluxe in PTP. Does look feasible to you considering that...I'm not really an electronician...?
Can one of you show me (on the attachment below) the signal path for the clean channel ?
I know that lots of people convert their old BD into 5E5 amp but the sound looks to be different to me and the blues deluxe looks to be mellower as I like.
Thank you in advance for your help !! :help:
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Does look feasible to you
NO
It looks like it will or has potential for being a nightmare just getting it working properly
go to your favorite guitar store find the TUBE amp of your dreams, then maybe you have a starting point.
but I could be wrong :icon_biggrin:
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There are quite a few Blues Deluxe and Blues Deville conversions done. Mostly to AB763 schematic/layout which is not that far from the Blues Deluxe "just the clean" channel. (also seen these converted into Dumble clones)
So, sure ……… I don't see why this would be a problem. You'd keep the cab, chassis, tubes, PT & OT and gut the rest and put in a new board for an AB763 with reverb but no vibrato. IF you are an experienced builder, then I think this would be reasonably easy to do?
You will need to add tube reverb since your Blues Deluxe has solid state reverb.
Here is a recent thread on one: http://el34world.com/Forum/index.php?topic=23927.0
Another thread where Mark Fowler shares a photo of his successful conversion: https://el34world.com/Forum/index.php?topic=23122.0
There is a YouTube of someone converting one into a Deluxe Reverb with 6V6's. You can do a search on that.
Look at Hoffman's info on the AB763:
https://el34world.com/schematics.htm#Hoffman_AB763_one_Channel_build_
AND look at Sluckey's excellent information on his Tweed Deluxe Reverb: http://sluckeyamps.com/tdr/tdr.htm
IF you're using a layout board and know how to work safely on amps and have some amp building experience, then this may be a reasonable project for you. IF you are NOT an experienced amp builder and this is a "first time" project, it is likely to be too ambitious for you.
With respect, Tubenit
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Just to give you a visual of what the amp looks like. I scanned the "original" schematic into my computer & opened it up with Windows PAINT.
I erased stuff that was either solid state OR the "overdrive" and came up with a schematic that's the "basic" Blues Deluxe. Which looks a lot like
an AB763 amp.
Then I added tube reverb.
IF you are knowledgeable enough and can work safely on the amp and have enough experience, this may be a reasonable project for you?
With respect, Tubenit
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Why not put the reverb where R15 is?
Then you get the 2nd verb recover/mix gain stage too.
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For starters, forget about the guy that said NO. He's no fun.
I feel like the newer Fender gear is over-engineered for what it is. So if you're looking for a clean pedal platform, I think you could do just as well starting with something simpler. Plus, if possible you want to limit your preamp to a single 12AX7. You only have 3 open 12AX7 cutouts on that amp, the other 2 would be for a one-tube reverb and the phase inverter.
Anything more than that you'll need more 12AX7 socket punches, which isn't the end of the world but... it can be avoided.
My choice for you would be the Normal channel preamp of Bassman AA864 (or similar), plus a one-tube reverb, then copy over the phase inverter and power amp from the Blues Deluxe.
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For starters, forget about the guy that said NO. He's no fun.
:laugh: Hey no pickin' on members.
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forget about the guy that said NO. He's no fun.
:icon_biggrin:
If the fender PCBs are anything like the Marshalls, you'll know why :laugh:
Hey no pickin' on members.
Thanks Willabe, but I'm sufficiently jaded & cynical to handle it :laugh:
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Hey no pickin' on members.
Thanks Willabe, but I'm sufficiently jaded & cynical to handle it :laugh:
:undecided:
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I think we all can agree that the task can be done. And with a little extra work can even add a tube reverb circuit. It's quite a lot more involved than putting together a Champ kit. The real question, does vitruv have the necessary skills?
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Hey no pickin' on members.
Thanks Willabe, but I'm sufficiently jaded & cynical to handle it :laugh:
:undecided:
I shoulda put a smiley I thought we were both being wise guys. :)
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I erased stuff that was either solid state OR the "overdrive" and came up with a schematic that's the "basic" Blues Deluxe. Which looks a lot like
an AB763 amp.
At the risk of seeming to be pickin' on members, that isn't the way I see the amp configured when set to "clean". The inverting 4560 causes the relays to be in opposite modes all the time. The schematic shows the relays in the "drive" mode. Reverse both relays for the "clean" mode.
I drew up a version with a possible tube reverb and a modified power supply.
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Hi!
whaou you're too fast for me. Let me have a look these coming these. I'm in travel for work and don't have much time.
In any case ...thanks !! ;-)
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Hey guys, I probably spent 4-5 min with my first morning coffee erasing "stuff" off the original schematic. I put very little thought into. I was simply trying to create a visual picture that there is a lot of solid state stuff/clutter in the schematic.
And ..... I was simply trying to point out that when the "clutter" is removed, that it is close enough to an AB763 (IMO) that it might be a reasonable task to simply put an AB763 board in. (yes, I am aware of the differences such as where the tone stack and volume is)
And R15 may be a better insertion point for the reverb IF you're trying to use the Blues Deluxe simplified schematic. However, I didn't have that in mind to actually use the basic Blues Deluxe design.
Instead, I was suggesting to use the AB763 schematic, layout and BOM, etc...…. since that was reasonably available and a proven design.
With respect, Tubenit
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Hi Guys,
I had a fast look to your relevant answers. My first idea was to build an AB763 but, with pedals the blues deluxe looks better to me, it is more friendly. With the deluxe Reverb my SL drive (xotic) sounded like a bee... (perhaps it is the sl drive.. ???) while the blues deluxe looks to work with every pedal. The princeton reverb 65 would also be a solution but I didn't have any occasion to try it (not so many guitar shop close to Grenoble in France)
This is why I consider the blues deluxe refurbishing.
2deaf your design looks really cool, you confirm me that in your design I need to add all the power stage from PI to speaker to complete the design ? Which software are you using to draw your diagram? May I ask you to have your file so as I try to make a full one with all the stages ?
I saw the post of Mike PR given by Tubenit (http://el34world.com/Forum/index.php?topic=23927.0). It simple and thus good for me (indeed I'm more an optician and my skills in electronics are...light). What is the impact to have only 2 preamp stages instead of 3 ? Power only ?
see you and thanks ! Vitruv
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I think you "should" build what you want to build and trust will meet your needs. If you like the Blues Deluxe with your pedals, then maybe that would be more suited to what you need. I think it should be relatively easy to draw up a layout for 2deafs schematic. I think there would be some generous help on the forum to contribute to your success IF you're needing that?
Having said that, I think an AB763 with a 12AY7 in V1, 5751 in V2 and a 12AT7 in the LTPI position using 5uf cathode caps in the first 3 gain stages instead of 22uf cathode caps would sound great and make a wonderful pedal platform. Just a thought. I am NOT trying to get you to change your mind.
It should be noted that a Deluxe Reverb uses 6V6 tubes and a Blues Deluxe uses 6L6 tubes which typically have more headroom in my experience.
The advantage that I see of an AB763 approach is there is SO much documentation out there to draw from.
I've participated on several forums for quite a few years and to date I can't remember anyone cloning a Blues Deluxe or just the Blues Deluxe clean channel?
With respect, Tubenit
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I thought a little more about the pre-amp and the available controls and came up with a variation that uses 'em all and can still be set for the stock clean settings. If you are in Europe, I included the export power transformer wiring in this one. If you go through with your plans and you have an export transformer, please confirm that your amp is wired as I have shown. The power amp is stock except for the impedance selector and the one Ohm resistors.
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Which software are you using to draw your diagram? May I ask you to have your file so as I try to make a full one with all the stages ?
I am using jschem.
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Here is another variation of 2deaf's schematic with a more " familiar" AB763 type reverb for your consideration.
With respect, Tubenit
2deaf, your schematic looks great & thanks for drawing it up!
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Hi !
Thanks for your great help tp you both. I will have a look in tomorrow or this we.
have a nice friday before the we !
V.
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I drew up a layout for you that should correspond to the 2deaf schematic but with a more "traditional/familiar" AB763 reverb circuit.
CHECK for ERROR! Compare with the schematic. IF there is a discrepancy, go with the schematic.
I have NOT checked the layout thoroughly with the schematic, so you will need to with a mindset that there could be errors or a discrepancy.
2deaf's schematic was interesting enough and well drawn, so I got curious as to how that might translate into a turret layout board? So, I drew up one.
I am NOT suggesting you should build this. I personally would prefer an AB763 schematic and layout with the mods I mentioned in a previous post reply #15 (such as 12AY7, smaller cathode caps, etc.....).
There is an editable ExpressSCH layout attached IF you want to use it and/or edit it to reflect 2deaf's choices in reverb circuits.
On non-proven designs/builds, I prefer a paralleled turret approach because it is SO easily converted into something else IF it doesn't work. :thumbsup:
Whatever you build, I hope you will end up with the amp you want and hope you will share your success! With respect, Tubenit
Edit: IF you want to match the LTPI plate "split resistors" on the layout, simply put a 9.1k resistor between turret 21 and the V4-1 pin.
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HI,
Further to your answers, advises etc and after few days of reflection, I decided to cancel the initial project to build a 5F4 tweed pro. This looks to be easier and I think I have more chance to have a working amp at the end ;-)
Anyway thanks for your help and effort. I you're interested I can post the 5F4 development.
cheers