New Revibe project

[SleepLess]

Hi fellas.
This is gonna be a EU version since I'm a 230V guy.  I intend to follow Sluckey's revibe schematic, layout and mods. This means buidling my own board, drilling my own chassis etc.
It is also gonna be a long wait for new updates since I haven't ordered any items yet. I actually start the thread off now because I need you guys to check the transformers options for me and tell me what you'd choose. I have seen that Sluckey used Weber trannies (at least the PT), Doug uses his own (Mojo?). I have also seen that Doug's PT is part Mojo779 which is actually a Gibson GA-5 PT. Interesting...

Here are the other options I have found. The first are Hammond and are convenient for me since I can buy them in Germany and save on shipping costs, and they are cheap too.

Power transformers with specs sheets:
Hammond  290WEX PT http://www.hammondmfg.com/pdf/EDB290WEX.pdf
Triode PT: http://site.triodestore.com/PT47610230Exp.pdf
Mercury Magnetics GA5-P-240: No 5V winding, 248V B+ (sorry, no specs sheet online, had to send them an email)
Weber WRVBPTEU: https://taweber.powweb.com/store/wrvbpteu.jpg

Output transformers:
Hammond 1750C: http://www.hammondmfg.com/pdf/EDB1750C.pdf
Classictone 40-18030: http://www.classictone.net/40-18030.pdf
Weber W022905: https://taweber.powweb.com/store/022905sch.jpg
Mercury magnetics FBFCO: nothing about it to say except that it has a single 4Ω output.

Chokes:
Hammond 194A, it's 4H: http://www.hammondmfg.com/pdf/EDB194A.pdf
Mercury Magnetics FRC, it's 3.5H (no more info about it).
Classictone 40-18040, it's 4H: http://www.classictone.net/40-18040.pdf

What would you guys pick for this project for the best possible sound/performance/reliability? I hope this thread can help many of you jump on board this project. In the meantime, if some of you could chime in and tell me what the best options are, I'd greatly appreciate it. Financially speakinh, the Hammonds are the best for me, but I'm interested in the best possible sound/tone I can get so if another costlier option is better, don't hesitate and say so.

Thanks again to this community, thanks to Doug for putting up this Revibe project and thanks to Sluckey for his twist on it. I'll try and build something that stands up to them!

[sluckey]

Financially speakinh, the Hammonds are the best for me, but I'm interested in the best possible sound/tone I can get so if another costlier option is better, don't hesitate and say so.

I like Hammond iron. However, the Hammond 290WEX power transformer is only rated for 1.05A filament current and you need 1.65A. It 'may' hold up to the extra current requirement but I would not use it. A better Hammond PT would be the 260C, but be sure it will fit your chassis. It's too tall to fit inside a chassis that is only 2.5" deep.

I used all Weber iron. My choice was based on price, physical size (PT inside the chassis), and filament current rating. The Weber PT is rated at 3A for filament current. I also bought two dual 100µF cap cans from Weber based on price. Total price for all iron and two cap cans was $82.00.

I don't think there is any advantage in using expensive iron on this project.

[SleepLess]

Thanks Sluckey, I was just about to pull the trigger and order all three Hammonds + F&T 100uf dual cans at $20 each... I'll go with the Weber PT and the Weber dual 100uF cans then and the Hammond OT and choke. I'll let you know when the boxes start popping up here.


Everything is ordered... Now's the wait time...

[sluckey]

Did you find a source for board material and turrets? Do you have the correct size drill bit for the turrets? Do you have a staking tool? And a drill press?

[SleepLess]

Did you find a source for board material and turrets? Do you have the correct size drill bit for the turrets? Do you have a staking tool? And a drill press?

I ordered the board from Doug and another one from TubeTown, where I also got the chassis, tube sockets and Hammond trannies. I bought Doug's staking tool and another one from TT as well:
http://www.tube-town.net/ttstore/Parts-for-Amps/Turrets-Eyeletts-Boards/Turrets/Turret-Stacking-Tool-TT-32::3850.html

I don't have a drill press yet but I'll find a way to make things work. Everything's on its way now. I still have to purchase a step cone drill to drill the chassis as well but I have found some affordable ones on eBay. I bought Doug's drills as well for turrets. Yes, I know that's a lot of extra but I'd rather have things I don't use for now than things missing. I'm the kind of guy who wants to move on and not leave a job undone for several weeks because of a missing part... I have a gig on September 20th and I intend to take the revibe there, along with my JTM45/100, for which I still have to buy the parts btw... 

[eleventeen]

You may want to look for a cheapo benchtop drill press from Harbor Freight or seek a used one on craigslist. Phenomenally useful tool.

[sluckey]

I'm gonna repeat this post from another revibe thread. It may have some useful info if you will be following my chassis layout....

Here's a pic of my layout. It shows top view. The first thing I did was to place the edge of the reverb tank flush with the front edge of the chassis and centered lengthwise. In my case that gave 1/8" clearance on each end. Mark and drill the 4 mounting holes.

The I marked a centerline all the way across the back side of the chassis. This centerline is 1.125" from the back edge of the chassis. All tube sockets and cap cans are centered and properly spaced on this centerline. Drill or punch these holes to size. Then center the OT between tube sockets. Mount the choke as close to the back edge as you can.

Once you have the tank and tube sockets drilled, everything else will just fall into place. Measure twice, cut once!

[SleepLess]

Thanks Sluckey! I have read Lego's thread as well but it's good to have this file here too!
I may purchase a drill press yes... I'll see how those turrets stacking tools turn out.

For guys who want to jump in, the Mercury magnetics GA-5 PT filament current rating is 3A. So it's also a good option, though pricier...

[EL34]

Did you find a source for board material and turrets? Do you have the correct size drill bit for the turrets? Do you have a staking tool? And a drill press?

I have all that stuff

[SleepLess]

Did you find a source for board material and turrets? Do you have the correct size drill bit for the turrets? Do you have a staking tool? And a drill press?

I have all that stuff

Hi Doug!
I know, you shipped my order two days ago! Thanks! 

[EL34]

Thanks for the order.


It's the summer slowdown and I can use the business

[SleepLess]

Hi.
The first box coming from Germany arrived this morning. Still waiting on the Hoffman and Weber boxes. I have taken two pictures for you. The chassis is actually 5cm longer than Sluckey's so there's more room and I placed the reverb tank right in the middle. Do you think it would be better if I placed it on the far right (closer to the IEC socket) or to the far left? I had a small bad surprise, the chassis has the IEC socket drilled and I thought it was a regular drill. It's not, it's meant for a large IEC socket with integrated fuse holder. I didn't order any of those... 

There you go, the chassis is really nice quality, the red dots that you see are the four screws spots for the reverb tank:





Thanks!

[EL34]

Just keep the output end of the tank away from the power transformer and other hum sources

[SleepLess]

Thanks Doug!
One more thing: I intend to have a faceplate done later on and Sluckey could you explain two things:
- The Slow/Fast switch: is it slow when you place it down or up?
- The LED: is it just a tremolo effect on/off indicator or does it blink according to the speed of the effect? Did you use a 5mm or a 3mm LED there?

It would look silly if the faceplate said "Slow" when it's actually fast... I hope I'm clear enough...
Thanks!

[sluckey]

- The Slow/Fast switch: is it slow when you place it down or up?

The speed range will be slow when the switch contacts are closed. Rotate the switch body 180° if it doesn't match the faceplate labels.

- The LED: is it just a tremolo effect on/off indicator or does it blink according to the speed of the effect? Did you use a 5mm or a 3mm LED there?

The LED blinks at the speed of the tremolo. I used a 5mm with a chrome mounting bezel similar to the one Hoffman sells. Color is important. Use red or yellow.

I would mount the reverb tank centered with the length of the chassis just for looks. The sensitive output end of the tank (red jack) will be far away from the PT if you have the jacks facing the tubes. A 4" long cable will be long enough. BTW, I made my cables using right angle plugs.

[SleepLess]

Cool, thanks Sluckey!

[EL34]

This Red LED works well for that
I use these on all my projects
http://hoffmanamps.com/MyStore/catalog/parts20.htm

[SleepLess]

Got it Doug!
One more thing: should the fuse still be 1A for 230V operation or should I bring it down to 500mA? Jeez, I never remember that! 

[sluckey]

I'd try the 500mA first. This is not a power hungry project.

[EL34]

current is current


just go .5amp for now and if it blows too easy, go with 1Amp

[SleepLess]

Hi there,
I'm back from vacation and deep into the Revibe build now. Here's where I'm at.

Chassis fully punched for top side components:



Almost everything installed, I need a larger punch for the cap cans and 6V6 socket, I got it yesterday only:



I used a center punch and Sluckey's drill guide to make drilling easier and more accurate. These center punches make you save a lot of time when you drill:



The board full drilled and turreted using TubeTown stacking tool. You don't even need a drill press, just a plank and a hammer. Figure it need five good hammer blows to install one turret... Who needs to go to the gym when they build boards as such? 



The board wired on the tubes side and all jumpers installed... I noticed afterwards some differences with Sluckey's pictures of his Revibe... I need to wonder why some of his jumpers aren't on my board...



Heaters wired. I just saw that two 6.3V wires need to go to the board... That V5 is gonna get crowdy on pins 4 and 9...



If you spot any mistakes, don't hesitate and say so!
Thanks!

[sluckey]

That's looking great! This is my favorite project. You're gonna really like it.

The board wired on the tubes side and all jumpers installed... I noticed afterwards some differences with Sluckey's pictures of his Revibe... I need to wonder why some of his jumpers aren't on my board...

Your jumpers are fine. Those four black jumpers on your board are actually on the bottom side of my board. That's what the dashed lines on the drill guide represent. I've attached a pic to show how I securely attached the underboard jumpers.

Also, some of the pics on my website show the board as it was initially built. But when I was tuning up the vibrato oscillator I modified the B+ nodes, eliminating one filter cap, power resistor, and one underboard jumper. Only the last two pics on the website show the board as it is today.

Heaters wired. I just saw that two 6.3V wires need to go to the board... That V5 is gonna get crowdy on pins 4 and 9...

If your PT has a center tap on the filament winding, just connect that to chassis and don't use the artificial center tap on the board. However, if you need to use the artificial center tap, may I suggest you connect the PT filament leads directly to the board, then run your filament string from the board to V5.

I have a faceplate available if you want to use it. The drawing is in the updated pdf at the bottom of my web page. I can easily modify it if you wish. You can see this faceplate on lego4040's revibe thread.

[EL34]

Got to agree with Steve

This is definitely one of the coolest things to build

They sound awesome and I use mine allot

It should be on everyone's bucket list

[SleepLess]

Thanks Steve and Doug! I can't wait to fire this one up!!!!

The PT I'm using is the Weber EU PT. It does have a HT CT. But I think I'm gonna do as you say anyway and solder the PT HT wires to the board and unsolder them from V5, it will look neater. I need to locate the articificial center tap on the board and get rid of it, I don't know where it is. 

Now I understand about the jumpers. I forgot that yours were running under the board!!! I decided to run mine on top so I have everything in sight if I need to debug. Steve you mention this: "But when I was tuning up the vibrato oscillator I modified the B+ nodes, eliminating one filter cap, power resistor, and one underboard jumper". Are all of these changes shown on the Revibe layout on your pdf file or must we only rely on the last couple of pictures on your website? Because I'm following the layout... 

A million thanks for your faceplate proposal but I have decided to change your layout a bit and will have the switch and indicator on the faceplate and not on the back... So I wouldn't be able to use your faceplate!

Thanks, tonight I'm finishing the board wiring and I'll start soldering in the components. I hope I have all of them!

[sluckey]

It does have a HT CT. But I think I'm gonna do as you say anyway and solder the PT HT wires to the board and unsolder them from V5, it will look neater. I need to locate the articificial center tap on the board and get rid of it, I don't know where it is.

The artificial CT resistors are the two horizontal 100Ω resistors shown in the lower left corner of the board in my layout. (Just under the bridge rectifier). Just remove the resistors and use the turrets as a tie point for yout PT wires. Don't forget to connect the real CT wire to chassis.

Are all of these changes shown on the Revibe layout on your pdf file or must we only rely on the last couple of pictures on your website? Because I'm following the layout...

All changes are incorporated into my layout and schematic in the pdf file. You are safe to use it. I took pics of this project as it progressed and posted to the website as soon as I had the revibe completed. Then I began tinkering the vibrato oscillator to improve (subjective, haha) to my tastes. So, the final circuit was modified slightly (only in the oscillator circuit) from Hoffman's original schematic. The last two pics on my website show those changes. I could not go back and change the intermediate pics of the board construction, etc.

Bottom line, follow the pdf. It's correct.

[SleepLess]

OK, thanks Steve. Is it right to assume that since I won't be placing the 2 100Ω resistors on the board these should be replaced by jumpers? I won't forget grounding the HT CT to the chassis!

[sluckey]

Is it right to assume that since I won't be placing the 2 100Ω resistors on the board these should be replaced by jumpers?

THAT'S WRONG! Just omit the resistors, don't replace them with jumpers.

      Look at the other side of those resistors. They are tied together. If you were to put jumpers there, you would have a direct short across the filament winding of your PT. And that would make you mad when you realized why those green wires from your PT melted.

I made that very error about 45 years ago!   

[SleepLess]

Hi!
Sluckey thanks a lot! Yesterday I finished wiring the board, tonight i'm soldering in the components. Pictures soon. Then I will take a break away from this build and get back to it in a couple of weeks. I have stuff cooking...

Sluckey I noticed a discrepancy between page 2 and page 4 of your pdf as far as the Vibrato FS wires are concerned! They are not located at the same spots (and the black wire on page 4 is gone, only the blue one remains!). Should I follow page 2 or page 4? (I followed page 2 but I can still solve this!).

I wasn't able to find your RG316 wire for the inputs, all I have is RG174. Is that good enough?

Thanks!

[sluckey]

Sluckey I noticed a discrepancy between page 2 and page 4 of your pdf as far as the Vibrato FS wires are concerned! They are not located at the same spots (and the black wire on page 4 is gone, only the blue one remains!). Should I follow page 2 or page 4? (I followed page 2 but I can still solve this!).

I wired my vib FS according to page 2.

??? Page 4 is the power supply detail and doesn't show anything about the vib FS???

I wasn't able to find your RG316 wire for the inputs, all I have is RG174. Is that good enough?

That's fine. I use 316 because it's Teflon insulated and the insulation absolutely does not melt while soldering.

Are you using the pdf file that's currently on my website?

[SleepLess]

??? Page 4 is the power supply detail and doesn't show anything about the vib FS???

No, that's page 3!

That's fine. I use 316 because it's Teflon insulated and the insulation absolutely does not melt while soldering.

Ok, great.

Are you using the pdf file that's currently on my website?

Yes, I downloaded it from your website.

[sluckey]

Hmmm, I'm wondering if we are looking at the same pdf file. Here's a screen capture of IE10 from a minute ago. Clearly, page 3 is the "board drill guide" and page 4 is the "power supply detail".

Open that pdf again and if the bookmarks table on the left does not look like the attached pic, then refresh your browser until it does.

There are 8 pages in the file and page 2 is the ONLY page that shows a blue wire headed to the vib FS jack.

You've seen lego4040's thread on his revibe build. I recently made several small corrections and additions to my pdf to help him with some issues he was having. It's possible you have an older version of the pdf?

[SleepLess]

Got it Sluckey! I had an older version I think I downloaded about a month ago!!! I didn't know it had changed!

So page 4 I was mentioning is now page 5!!! You still see the blue and black VIB FS wires on page 2 but only one red VIB FS wire on page 5.
But I followed page 2 so it's all good. I'm gonna reprint page 2 in case there are some changes before I solder in the components. Speaking of which I only have a 220uF 35V cap instead of 250uF 50V, is it gonna be good enough?

Thanks Sluckey!

[sluckey]

So page 4 I was mentioning is now page 5!!! You still see the blue and black VIB FS wires on page 2 but only one red VIB FS wire on page 5.

       I knew we would finally get to that! You caught me. I'm guilty. But, page 5 was meant to only show how to place the major components inside the chassis. Don't pay any attention to the details of the board in that page. From now on I'm just gonna represent the board as a green rectangle on any chassis layout drawings.

Nothing has changed in the page 2 board layout so you're good to go.

 

I only have a 220uF 35V cap instead of 250uF 50V, is it gonna be good enough?

Actually, Doug's original schematic calls for a 220µF cap. So does my redrawn schematic. But my layout shows a 250 and I actually used a 250 because I had one on hand. Damn! You caught me again. 

Since you have a 220µF on hand, I highly recommend using it.

[SleepLess]

Hi!
A last update before I take a break away from this build. I didn't order any resistors for the build since I had plenty of them but I have actually found out that I need 4 values I didn't have. New order needed... I used carbon film and not metal film like you guys did, I hope this won't cause any issues or sound worse... I haven't been able to find the 5.1MΩ resistor for the speed pot, I have only found either 4.7MΩ or 5.6MΩ but not 5.1MΩ...

You'll see missing resistors on the board, that's because I didn't have them. I need 10K, 1K 2w, 330K and 4.7K. The 2.2uF cap hasn't been installed since it goes with a resistor I don't have so I will install both when the resistor comes in.

Thanks!

Cap cans installed:



Top view:



Almost fully finished board:

[sluckey]

I haven't been able to find the 5.1MΩ resistor for the speed pot, I have only found either 4.7MΩ or 5.6MΩ but not 5.1MΩ...

You may not even need that 5.1M resistor. Try it without it first.

The reason I added that 5.1M resistor across the speed pot was related to the additional capacitor for the "slow" range. When in slow mode, my oscillator would drop out (quit working) when I turned the speed pot to zero. Putting that resistor across the pot cured the drop out problem.

So, if your oscillator works fine in slow mode with the speed pot set to zero, you will not need that resistor. And if you find you do need that resistor, then use your 4.7M or 5.6M. Either should work. The smaller the resistor, the faster your oscillator will run.

[SleepLess]

OK, thanks Sluckey!

[lego4040]

Looking good man, You fire yours up yet? I finally got rid of a hum and I am in love. This thing paired with the AC 15 is a dream, I did not use the 5.1m resistor on the range and have no problem with it either. I had a issue with a ground loop and finicky 12ax7 for V4. Now I need cabs for them

[SleepLess]

Not yet lego! I need some parts and have a tweed harvard build going now... I'll get back to the Revibe in a couple of pics. I'm near the end though.
Cheers!

[lego4040]

Cool, Now Dougs got his Princeton Reverb build going. Now Im gonna have to build that next, but find a suitable tweed cab instead of a Blackface

[Willabe]

Mojo will cover any of the cabs they build in any of the coverings they have. Also they put any grill cloth in that they stock too.


               Brad       

[EL34]

Yep, Mojo can make you anything you want with any covering combo
You can even make it a head instead of a combo

[sluckey]

Any progress?

[SleepLess]

Any progress?

Hi Sluckey!
Not yet! I'm getting back to it in about ten days. I'll report back! Thanks!

[Mike_J]

I made a revibe with Torey T's help some years ago.  I tortured the poor man with my ignorance.  Had a bad solder joint on a ground that caused a lot of hum.  Once I found the bad solder joint the unit made no noise at all.  Use it with my 5f6a and 5e3 builds.  Never have been happy with the vibrato it has.  Seems somewhat anemic.  Sluckey did you correct that and where do I find a schematic if you did. (Looked but couldn't find it)  I am sure I would use it more if the vibrato was better.

Thanks
Mike

[sluckey]

Tore has a version of the revibe that uses a simple tremolo oscillator to wiggle the cathode bias of a typical gain stage, much like the Vibro Champ. I would expect that version to sound kinda ho-hum compared to the version that Hoffman offers. Maybe that's what you have. Show us a schematic and I can say for sure.

Hoffman's revibe (I don't know who really came up with the circuit) uses a harmonic vibrato circuit borrowed from the 6G12 amp. It has a complex, lush sound like no other tremolo. You can find Hoffman's schematic righ here. Or my schematic is on my website. Or you can go to Weber's site and see both versions.

[lego4040]

Interested in if you have it running yet and if so which tube you use for V4&5. V5 especially, mine was real picky about it. I won't get to play again in a few days and I'm interested in if it fires up ok

[SleepLess]

I'm waiting for some more parts to arrive before I finish it up. I should be able to get back to it in about a week, two at most.
As for tubes, I purchased a set of good NOS tubes, it should be ok.
Thanks Lego!

[SleepLess]

Hi there!
I have finally found the time to get back to this project and it is now nearing its end. Here's a picture:



I have a couple of questions though, if you don't mind helping me out:
I have a power input that has a fuse location:



Would you mind telling me how I can use it? Normally the Live power cord wire goes to the tip of the fuse holder and then another wire goes from the side tab of the fuse holder to the left of the ON/OFF switch. How do I implement that with this type of mains/fuse unit?

Then another thing: Sluckey you use a 6V indicator lamp, I installed a 115V lamp that I had available. The Weber EU PT has a 120V wire: should I solder it to one tab of the lamp and then use another wire to reach the other tab?

Another thing: I made a mistake while soldering the ground buss wire: I passed it through the Tone pot ground tab as well. Will that be harmful or can I leave it as it is? Here's a picture:



And the last thing: The LED has a short lead and a longer lead, which goes where on the board?
Thanks, can't wait to fire it up!!!

[sluckey]

It's about time!

How do I implement that with this type of mains/fuse unit?

Looking at your pic... The left lug is the fuse. Connect that lug to your power switch. The other side of your power switch connects to one primary wire of the PT. Connect the right lug directly to the other primary wire of the PT. The middle lug should be the ground connection.

I installed a 115V lamp that I had available. The Weber EU PT has a 120V wire: should I solder it to one tab of the lamp and then use another wire to reach the other tab?

I don't know. Measure the voltage between that 120V lead and the common lead on the PT primary. If it measures about 120VAC give it a try. But, if your indicator lamp is a neon bulb type (I suspect it is) you may be able to use it directly across 230VAC. Just to be safe I would put a 100K .5W resistor in series with one of the lamp tabs. You could just use a small cable tie to strap the resistor to the body of the lamp housing.

I passed it through the Tone pot ground tab as well.

That's fine.

The LED has a short lead and a longer lead

The cathode is the short lead and there may be a slight flat on the body of round LEDs. If you can see inside the LED the cathode is the larger electrode. See this link for a very easy read on LEDs...

     http://electronicsclub.info/leds.htm

[SleepLess]

The LED has a short lead and a longer lead

The cathode is the short lead and there may be a slight flat on the body of round LEDs. If you can see inside the LED the cathode is the larger electrode. See this link for a very easy read on LEDs...

     http://electronicsclub.info/leds.htm

It's about time, you're right! Too many guys come to me and ask me to fix their old amps... I don't even have enough time for my own stuff. I guess I can't say no... 

OK, so on your layout, is the LED cathode the black wire or is it the yellow wire?
The rest is done. I soldered the 120V PT wire to one tab of the lamp and didn't connect it to the other one.
Thanks!