blackface vibro champ

[RetiredUnit1]

So I used HTTrack to download *all* the fender layouts and schematics on to my hard drive, and when I'm bored I like to look at different models. I built an HTML so the table of contents is listed on my browser and I only have to click on it to pull up the .pdf

Much to my surprise I see a Blackface Champ with tremolo. Whut? I had no idea such a beast existed. My first amp was a single ended class A 6v6 Rickenbacker B9A which is very much the same. Since that was stolen in the late 70's, or early 80's I forget, I decided I was going to add this VibroChamp to my list, since it is EXTREMELY close to the same schematic but I can easily find a transformer for it. The Rickenbackers were so rare, no one seems to even know they existed. And they were prone to dying young in smoke, as mine did before it was stolen.

Anyway, as I'm realizing this design is going to be hard to fit into a small chassis I decided I'll put the electrolytic caps up on top, it is after all a blackface and they all have the caps on top to make more room for the circuit board. This introduces the difficulty of finding a not too big, not too small box to go on top of the chassis to cover the caps.

So I decided to take a break and look at the new posts and see someone discussing an enclosure and BINGO I realized I could use a PEDAL ENCLOSURE instead of a sheet metal fabricated cap cage. The 1550P is in "The Goldilocks Zone", just right in H, W, and D!!!

I still have a few details to work out, but HEY LOOK a new use for a Hammond Enclosure!!!!!!!!!



My inspiration:

 

[Blooze]

Cool! I just re-capped my silverface vibrochamp and modded it to get blackface voltages. Mine had the larger Princeton power transformer in it.

 

[RetiredUnit1]

Cool! I just re-capped my silverface vibrochamp and modded it to get blackface voltages. Mine had the larger Princeton power transformer in it.

Did yours have the 3 way can cap, or separate capacitors? The blackface has the 3 in one, but the wholesale price is HIGH! Gaaa, I can get the mod caps for $1.85 each, lol... I was going to use the can cap till I saw this. Even with the enclosure my total cost will only be about 12 bucks....

 

[Blooze]

Did yours have the 3 way can cap, or separate capacitors? The blackface has the 3 in one, but the wholesale price is HIGH! Gaaa, I can get the mod caps for $1.85 each, lol... I was going to use the can cap till I saw this. Even with the enclosure my total cost will only be about 12 bucks....

View attachment 50997

It did. It had a 20/20/30 in it. I replaced it with a 20/20/20/20 for an extra stage of filtering. I replaced the rest of the electrolytics with Vishay TE series. If it ever goes I'll leave it in there for looks and put individual caps inside the chassis. More than enough room.

 

[RetiredUnit1]

Well I did some more work last night before pulling the guitar out. I have the OT and cap cage shaded as watermarks in the back layer in the positions they'll be in. I did manage to fit everything in that tiny 10x6x2 chassis! Got the power ground/preamp ground busses separated, and picked out some very small poly caps for the tremolo since the signal doesn't pass through those. And today is housework day and OFF I GO.

Played till 2:30am last night. Ugh. 11:11 and I'm going to go make breakfast now, lol...

 

[RetiredUnit1]

SO....

You know how sometimes you get blinders on and you can't see what's right in front of your eyes???

I was so concerned with trying to fit this BFVC into the same size chassis I used for the 5F1 Champ that I failed to notice there were FIVE knobs and two inputs on the BFVC instead of one knob and one input.

Well DOH bigtime.... I did the math and a good size available Hammond aluminum chassis was the 12x8x2.5 and the 13X7X2. I don't like the number 13 so I picked 12x8, lol...

Now I have plenty of room to put the power capacitors inside the chassis on the circuit board, making it less expensive to build and easier to plan and build. I've mocked up the front panel, and was wondering..... what you all think? btw, I spent over TWO HOURS making the mockup for the witch hat knob, lol. Most of that time trying to find the right font. I settled for "the five isn't quite right" while getting really close to the rest of the numbers.... and after I put the knobs on I was really glad I had the 2.5" tall face instead of the 2"!!!

 

[RetiredUnit1]

So I just finished the layout for my BFVC, Blackface Vibro Champ. The blank chassis is on it's way in the mail, and I think this came out rather nice. I ordered some TINY panasonic capacitors from Mouser along with the chassis. They're the size of Chiclets, are 400v and are dirt cheap! You can see them all in a row, it's how the Tremolo works and are used in a non-signal path.

Kinda wondering how they'd sound if used in the signal path, thinking about doing a normal champ just to try it out........

This was a fun amp to draw, looking forward to building it!

 

[oldtone]

It did. It had a 20/20/30 in it. I replaced it with a 20/20/20/20 for an extra stage of filtering. I replaced the rest of the electrolytics with Vishay TE series. If it ever goes I'll leave it in there for looks and put individual caps inside the chassis. More than enough room.

Blooze, I'm going to quibble with the tubes power dissipation a bit(as in the schematic you posted). The plate voltage is 367v and the cathode voltage is 16v. The voltage across the tube is 351volts, not the full 367. So the plate dissipation would be a bit lower. I believe this is correct, but I'm somewhat under the weather and have been for a while. Medical appointment forthcoming.

 

[cdwillis]

This is a really cool project. I've been researching something similar among all these old blackface Fender schematics.

I commented on the Psionic Audio livestream last week saying that I've been building pedals and laying out pcbs for a couple years now so I wondered if he thought a Deluxe was too big of a project for a first amp build. Lyle suggested a tweed champ first then building the deluxe. A tweed champ seems like the kind of amp I'd build and never really use. So I was looking at Princetons then Vibro Champs. What I think would be cool is a Vibro Champ with the bias tremolo with a Princeton sized cabinet and 12" speaker. I'm afraid I'm biting off more than I can chew since I still don't know shit about what transformers to use. A lot of this is trying to have an amp with a fuller response without the bass farting out.

 

[RetiredUnit1]

This is a really cool project. I've been researching something similar among all these old blackface Fender schematics.

I commented on the Psionic Audio livestream last week saying that I've been building pedals and laying out pcbs for a couple years now so I wondered if he thought a Deluxe was too big of a project for a first amp build. Lyle suggested a tweed champ first then building the deluxe. A tweed champ seems like the kind of amp I'd build and never really use. So I was looking at Princetons then Vibro Champs. What I think would be cool is a Vibro Champ with the bias tremolo with a Princeton sized cabinet and 12" speaker. I'm afraid I'm biting off more than I can chew since I still don't know shit about what transformers to use. A lot of this is trying to have an amp with a fuller response without the bass farting out.

The champ, vibro champ, princeton, and bronco all use the same transformer specs. So far I've found that APD has the best prices on Heyboer transformers. https://shop.amppartsdirect.com/collections/apd-custom-by-heyboer.

Just about everyone that sells transformers know this is the hardest thing to spec in an amp, and are more than willing to talk over phone, or by email and recommend part numbers. They'll usually give the most expensive models, so be sure to say ask for all the models.

If you go to their page and click on the magnifying glass at the upper right, then type in vibro champ you'll get this (see pic). They have Mercury Magnetics as well as Heyboer for a higher price. I live really close to Mercury, so I've always driven there to pickup iron, but in the past 7 years they've really gone up.

For this amp I'm using the APD-8019H and the APD-8030H $89 + $45. The blank chassis (bottom pic, I have to drill the holes and use a small composite circular grinder for the square holes) cost about $30. Of course there's freight involved too.... It's not cheap but is usually over a thousand less than buying a reissue!

The most important part about building an amp, especially the first one is to GO SLOW. Come up with a system you use for which wire goes where. I usually use the side of the amp as a reference, like second tube from the left, pin 3 connects with second .022 capacitor from the left, etc.

That's also why I do my own layouts and use so many colors. All yellow wires will drive you crazy and were used in the original fenders because, as Leo told me when I was 13, "I only bought that crap because I got a million feet of it for $1000." My best friends dad was Leo's best friend. They were next door neighbors when they were young. Leo didn't play guitar, so he had Les try them out and give him feedback. In fact when I met Leo he was dropping off his post CBS G&L guitar and Music Man amps for Les to try!!!!

He also told me if I ever decided to build any of his clones, to use the best parts I could find because he used the most inexpensive stuff he could get to make amps affordable for the masses. That's why I use cliff jacks instead of metal (since I can put the grounds where I want them) and generally always make my own layouts a bit roomier than his were.

If you decide to build one feel free to PM me with any questions or problems. There's also other people on this list more than qualified to answer many questions!!!!

 

[RetiredUnit1]

Well.... This is kind of a test. From Visio I made JPG's of all the pertinent pages of my layouts for the amp, chassis and circuit board. I used a site called pdf24.org to arrange these pictures into a PDF, then I uploaded that to my google shared drive. On a different forum the actual picture appeared of the first page, but I think that option must not be enabled or uhhhh huh huh huh ...... something

Anyway, this shows why I go into so much trouble when I make my layouts to be actual size, because I can make copies of the main page, then delete everything except the holes I need to drill.....

T.E. BFVC.pdf

drive.google.com