The Amp Garage

The 1 ohm resistor needs to be 1% tolerance and I use 3 watters just to be massivly on the safe side in case the tube melts itself down. It gets super hot around the chassis near the output tubes and you want the 1 ohm to stay at 1 ohm and not drift. If you can only get 2 watt resistors, leave as mu...

Tung sol reissues and EH tubes are all Sovtec made, if I had to put money on how many rejected tubes out of say 100 from Sovtec and 100 from JJ, my money`s on the JJs having less poppers! Also in regards to customers amps, once they leave your hands you have no control, they could send the amp bunge...

The cathode should read 14,470 to ground.
You have the 1 meg grid resistor?

If you have the parts and time go for it, but just for the future if you place a fuse in the OTs B+ feed you can save the recto tubes from having excess current from being ripped out of it. Just having a AC mains fuse takes too long to blow. Some tubes are just not gonna fail until you get enough he...

I concider a 2-12 combo" to be the way to go for the needs that you state. A 2-12" amp with neo mag type speakers will be way lighter than your back breaker you have( I hate working on that amp just due to there weight! between chassis and EV driver!) I would also concider that some 50 to 60 watts o...

Swapping the OT leads should not have done a thing to the B+ voltage, did the wires go back on pin 3 of each output tube? What is the B+ on the red center tap of the OT, between 420 and 460? You should have the PT and or a power supply dropping resistor getting very hot with this issue. If you get t...

These amps need the fan to run or the output IC packs go outs to lunch when they get hot enough, sometimes with out taking out the fuse. In a darkened room you should see that 12ax7 tubes filament light up if the tube and it's power supply section are ok. These amps also have a mute circuit that fai...

A JJ from Euro tubes that test in at atleast 88%. Note with these amps if you are still lucky enough to have the stock OT in it that the amps bias circuit is very much on the edge of having enought bias voltage to tame a good set of outputs. As such if the the outputs red plate or short out from red...

If this is not a re-issue amp have the bias supply filters been changed out, even if this is a re-issue amp the filters they use are crap and some border line defective even when new! Your recto tube could also be weak and slow to recover. The stock fender blackface and early silverface bias filters...

One or both of the tubes must be arcing at a certain level of drive signal/ current draw.
The JJs are a far better built and sounding tube all around and has it way over the Rusky when drivin hard not only in cleam mode so I would just stick with them and be done with it!

Next time you change your guitar strings save the D string if its wound, they are a great size to run in and out of preamp tube pin sockets to clean and polish them up.
A wound G string from a acoustic set may also work.

JBL did some starnge crap! My friends Fender champ has a stock JBL 8 incher in it and its magnet tag is stamped 8 ohms, yet it is the needed 3.2 ohms that the champs OT needs to have. Also a big time thing to note with JBL cone drivers is that red is not positive, yup! If you hook up a 9 volt batter...

Blowing the HT fuse when all the tubes are out of the amp is new one on me after my 42 years of repair work I gotta say!! I am sorry to say this but the wiring around the output tubes is a mess, and that photo does not help much, but I do think I see a issue. Your red bias test points and resistors ...

If you go and look at the tube spec sheets you can get a feel for how much power your build(s) output, in fact I can not belive that you have built more than one amp from the get go without consulting these charts! A difference of 15% in wattage from these charts/specs will hardly be heard in terms ...