What's on your Amp workbench?

[ZMB KLR]

97 hot rod deville 410

Bought off craigslist. Originally listed $450 and had one bad input.

When I showed up, the first words out of the seller was "the price has come down because the other input is acting up"

It still worked but it was loose.

Ended up at $375. Went home, cleaned it up and ordered two new inputs.

[DaJeepster]

Just parts now. Will be attempting my first amp build soon. The goal is a Tweed Champ head with the tubes on top. So far a blank chassis and a MojoTone small parts kit. Time to start cutting holes when the transformers get in.

[irv78]

hi, i'm making a 5e5 (cathode biased) build at the moment. single channel - one volume one tone.
with a slightly modified layout for a "valvewizard"-style grounding scheme. here we go:

[jimboyogi]

Looks awesome irv!

I like the ground bus, should work better than the original ground scheme for minimising hum.

The stacked 1K 5W resistors, is that because there wasn't room for one 470R 10W on the board?

[irv78]

Looks awesome irv!

I like the ground bus, should work better than the original ground scheme for minimising hum.

The stacked 1K 5W resistors, is that because there wasn't room for one 470R 10W on the board?

Thanks jimboyogi

I'm following a pretty strict ground scheme (all jacks isolated and just one ground connection for the circuit near the input) and I hope it will work out as intended.
Actually all four 1K are in parallel for the required 250R (I already had a couple of those at hand).

[jimboyogi]

Looks awesome irv!

I like the ground bus, should work better than the original ground scheme for minimising hum.

The stacked 1K 5W resistors, is that because there wasn't room for one 470R 10W on the board?

Thanks jimboyogi

I'm following a pretty strict ground scheme (all jacks isolated and just one ground connection for the circuit near the input) and I hope it will work out as intended.
Actually all four 1K are in parallel for the required 250R (I already had a couple of those at hand).

Makes sense, and the resulting 20W resistor should be very reliable!

Re. grounding, I have been using a very similar idea on the boards I have made, a wire 'bus' along the lowest run of eyelets, with all circuit grounds going to the eyelet/s closest to their relevant power supply filter cap ground. Just one ground point at the input side of the board, at the V1 PS filter cap ground, and I run a wire to here from the isolated input jacks. From this setup I am getting so little hum that now hiss is by far the loudest noise! Should hopefully work the same for you

[JforJag]

I combo-sized my '64 Tremolux. Unfinished and nekid soundcheck:

[jimboyogi]

I combo-sized my '64 Tremolux. Unfinished and nekid soundcheck:

Awesome!

[jimboyogi]

Got this on the bench ATM. Been in the pipeline for nearly 12 months, so will be great to get it finished!

Front


Back


Guts

[sookwinder]

when do I get to hear it/play it ?

[jimboyogi]

when do I get to hear it/play it ?

You kinda have already, in it's prototype form

[sookwinder]

yeah ... but in its full glory is the way to feel the energy ... maybe with a 67 Riv plugged in ?

[jimboyogi]

yeah ... but in its full glory is the way to feel the energy ... maybe with a 67 Riv plugged in ?

Geez, OK, but only if it's a 2 pickup model.

Should be done in a couple of weeks.

[sookwinder]

Slowest amp build I have ever done ... essentially 10 moths from start to stop and as usually happens you need to rush things a little at the end.

My nephew graduated High School and is starting an Audio engineering course next year, I built him one of the amps I have designed ... a Vibro Groove.
On this build I have managed to locate teflon wire of many different shades. It makes for a very clean build. Other than a dodgy earth solder joint which stumped me for a few days last week, the amps was perfect. In fact voltages are almost like for like with my amp that was built almost 2 years back. The coloured wire really helps with layouts, fault finding and isolating sections of the circuit.
Highly recommend slow amp building

Daniel loves it. Especially the master volume ... he can get the creamy sound without his mother shouting out to turn it down !
[there will be a reverb unit coming soon that matches it]

Bottom pic shows my Vibro Groove amp with the newly put together one for Daniel. My one has the SF cloth, the other one with Fender Style Beige Brown Grill Cloth is Daniels.

[Riffraff]

I spotted a deal on a non-working '51 Stromberg Carlson tube PA on CL for $100.



When I opened it up I was surprised to see someone had already replaced all of the electrolytic caps. It only took me a few minutes to figure out that the problem was the power switch on the volume pot was bad.



I put in a new power switch, added a fuse holder since it didn't have one and replaced the badly worn 2-conductor cable with a grounded cable.





The amp is single ended 6L6 powered, 5Y3 rectified and has 6SJ7 metal can octal preamp tubes.



I stumbled onto a deal on some vintage glass and grabbed a nice old '50s brown base Sylvania JAN 5Y3WGTA rectifier and a short body Sylvania 6L6WGB to replace the 6L6 coke bottle type. I thought it would be a good idea to change the power tube before I cook it.

Fresh Vintage glass - tubes replaced



6SJ7 metal can octals. I have a NOS 6SJ7GT Sylvania on the way to me to try out in it.



So the big question, how does it sound? I made a short clean & dirty clip using this V30 loaded 212 cab.



Here’s the clip http://www.youtube.com/watch?v=SZE-Wox6ZUE" onclick="window.open(this.href);return false;