The Amp Garage

this is excellent.

After hearing the Wreck I tried a bunch of my amps, and my Weber Java build and one of my Marshalls buzz enough to notice slightly but much less than the Wreck. The others (couple 18 watt variations, a few other Marshalls) seem pretty quiet .. I probably would have never noticed any of the other am...

all of those radial ones should be good.

I'd just double check the axial ones for leakage.

well you actually have two choices you can use 1 resistor for all 4 tubes and use 210-220 at 10watts or you can use 1 resistor per tube at 860-900 and have them be like 2-3 watts. you'll need one capacitor per resistor as well in that case. you should get the grid leak resistors, it's bad to run you...

I assume that this OT is so noisy is an indication that it is not as healthy as my other amps that are subjected to the same cranked output into heavy attenuation but do not make any (or much) noise diagrammatiks - living in a Condo with neighbors on both sides makes an attenuator a necessity, and ...

It's either 420 or 430. The plate voltages on V1-V3 (and the voltage on the cathode of the cathode follower) were kind of low, so I bumped them up. I changed some resistors and removed the resistor between the last two filter caps to jack the voltage a little bit on V1 & V2. Seems to have worked, b...

at least nothing blew up!

you should have about 8-10 watts of volume.

the breakup volume shouldn't be too loud.

actually what value of cathode resistor are you using?

I am putting together a parts list for the #183. I would like to use metal film resistors as much as possible if at all possible. I've noticed in lists for #124 and #102 the resistor values float from 1W for Carbon Films to 1/2W for Metal Films for the same resistor, depending on the list. Also, ho...

remember when you are attenuating that much that the transformer is putting out 100 percent of its output. Say if you cranked the amp and then attenuated it down to conversation level the transformer would still be working hard as hell. that's going to increase any normal electrical shenanigans such...

you have a legendary chassis

there's really no reason why that has to be a 3 watt resistor. Maybe it was done that way following conventional wisdom that with Carbon Composition resistors, one should go high wattage for lower noise? As Jana said though, it matters not in that NFB position. it doesn't matter in that position. T...

there's really no reason why that has to be a 3 watt resistor.

it's a dc coupled long tail pair using fixed biasing.

early hiwatts had v3b as the direct coupled driver for the voltage reference.

later hiwatts use v3b as an external voltage reference for the phase inverter bias.

well I'm stumped if it's not giving you any output power even with only 2 tubes.

you should be able to pull at least 7 watts across an 8k output transformer.

what size did you make your shared cathode resistor?

and what did you bypass it with?

beats me. I'm just going by the numbers that are in your schematic. I cheat a lot. If I need to build an amp I usually go looking for a schematic of an amp that has the voltages on it that's close to what I want to build. double the numbers to double the output tubes, halve the numbers to half the o...