The Amp Garage

Firestorm wrote:Who is the guy that used to build Gerald Weber's tweed cabs? He's moved to Washington (state) so is nearly non-viable for me economically, but he has some recipes.

John Mergili at Mergili innovations.

Check the 7199. Test the film caps connected to cathode of the pentode section. If they test good, then try elevating the filament supply with a voltage divider off the the last preamp supply node. 1/10 ratio should get you about 25 v , connect to the filament center tap . Also bypass the voltage di...

I recently got a TC ditto looper. Very simple, good sound quality. I do have trouble getting in sync with it though, no quantizer. I use it for practice only or song writing.

Martin nails it again. These two resistors drop the 48 volts to 15 or so. I re solder every fender that has these whether they need it or not. Many of them appear cracked and not just de soldered. I think the heat combined with the rohs solder and the weight of the resistor causes the issue. I've ne...

CE Sells or used to sell both lamp assemblies, the cheaper chinese ones are the problem. It could be some other issue though. If its wired like a fender and the filament powers the tubes but not the lamp and the bulb is good, must be the lamp holder. I have no idea why the filaments did not light up...

I have had issues with the cheaper Chinese lamp assemblies. I only use the higher grade ones now, only cost a buck or so more.

I prefer the switchcraft 226 right angle to the g&h becuase the g&h loosens up and the back falls off and gets lost. Never had any issues with the switchcraft 226. I can only imagine what might be the cause of the failure, shorted maybe. What cable did you use? I have had the crimp cut thru to the i...

Yes, parallel v1a/b. See the 50k plate load. I often use two 100k's. Lowers the output impedance and reduces noise a little. Just a little more hair too.

Oh, yeah. Forgot what I did. That's normal. Anyway, I have done quite a few of these, even repeats for clients. The only issue is, its loud ! So get an attenuator. I've tried all sorts of MV's and don't like any of them for this style circuit. The Clean channel becomes a stock Blackface normal ch. T...

Train wreck third stage. See my website for schematic, longhorn mod .

might try grounding the preamp up by the input jack. I have had strange issues when things are grounded together like it appears you have.

Best way to reduce hum in a champ is to add another filter cap and resistor to the filter bank. I used a 20uf x500 from the rectifier , then a 620 ohm 5w , then the stock filter bank. I used those values because that's what I had. No need to mess with the filament circuit. If the can is good and has...

Try elevating the filament supply., if cathode bias then ground the filaments to the power tube cathode. Reworking the ground scheme might also improve the hum. I like to have all the grounds of the preamp at the input jack or close. Screen supply and before closer to the power transformer. Etc.

roberto wrote:

billyz wrote:And those old ceramic treble and PI coupling caps just sound right. New ceramics not so much.

which kind of new ceramics are closer to the original ones?

Don't have a clue. I use polystyrene in new builds. They don't dont sound like ceramics , but they sound good. Sweet n silky.

The 16/3 awg power cords are usually too big to fit most fender vintage amps. I use the 18/3 awg . I get the 12' that have the iec connector, then I can use it for either. Cut off the end. I use these pliers. http://www.amazon.com/gp/product/B002PIC00S/ref=pd_lpo_sbs_dp_ss_1?pf_rd_p=1944687442&pf_rd...