The Amp Garage

Hi guys have this circuit with pedal to switch between Plexi/800 and I recently lost bass control. Pot was working but now does nothing to increase decrease bass. How do I diagnose where the issue is? I reflowed all solder joints no improvemnet. Wondering if it’s the pot?? Ideas? Can post pics of th...

Two bright switches on this build. First seems to cut mids?? Second is a bright shared by the Plexi and 800 circuit. Any idea what the switch between the normal and bright pots is supposed to do?

Thanks !

Thanks guys. Here's a pic for reference. First master is definitely a pre PI second connects to the output of tubes and bias pots?

Hey guys I'm trying to resurrect a build of David Roots that was finished but had a couple issues. It is a Plexi/JCM 800 with a footswitch for each channel. One input standard volume tone stack except bright and normal can be blended together and two bright switches. What perplexes me is two master ...

It is with a heavy heart I would like to inform friends, associates and fellow Amp Garage members that at 7:00 am, July 23, 2017, Mr. Root succumbed to his battle with cancer and passed peacefully under the medical care and compassion of the Chilliwack Hospital staff. He is survived by his wife Donn...

Hi guys, Here's an interesting one.... Noticed last night when using pedals on my Jackson Ampworks Britain 4.0 a popping sound when engaging the looper pedal. At first thought it was the true bypass on the pedal leaking DC but after removing it from the circuit the rest of my pedals make a popping n...

I notice that Derek shares his TW Rocket with a lot of younger musicians, students ect. . I think it's commendable that he shares such a rare instrument with young aspiring musicians.

Can anyone here identify this 18 watt circuit? It's a Trinity amps 18 watt amp looks like a kit trying to determine what model. Has a boost switch inside. [IMG:1024:768]http://i796.photobucket.com/albums/yy247/jeeping/454F48B1-1D47-4446-9884-19CC60E31AF6_zpsy2u6ulxk.jpg[/img] [IMG:1024:768]http://i7...

Do you mean disconnecting the lead from the rectifiers? You would have pulsating DC, but you might get some indication that the transformer and rectifiers are ok. What happens if you monitor the voltage with the standby switch in standby? That isolates the PT, rectifiers, bleeders, and reservoir ca...

martin manning wrote:Reservoir cap failure?

martin manning wrote:Reservoir cap failure?

I am going to replace to see if it is the reservoir cap. Curious if I disconnect the cap and remeasure power supply voltage if it doesn't drop safe to assume the cap?

When I say diodes I mean the diodes in the rectifier. They'll be connected to the first filter cap and should read roughly 395VDC. I'm trying to determine if something is drawing excessive current and pulling the HT down. 395 at rectifier I believe. Should be a little higher because the tubes will ...

Yeah so you say the voltage is dropping on the EL34 plates, is it dropping on the end of the rectifier? Or at the first filter cap? Have you checked the bias of the EL34s recently? Yeah so you say the voltage is dropping on the EL34 plates, is it dropping on the end of the rectifier? Or at the firs...

Littlewyan wrote:Ok so does the actual HT change? Measured at the diodes?

Also that link goes to a buffered effects loop page

http://ampgarage.com/forum/viewtopic.php?t=28589

HT? If this is heaters they don't change. Just b+ and screens.

So you're saying the AC doesn't change the whole time this is happening? I'm assuming this is an Express? I should try to be less vague :) It's an Express documented here with a voltage chart. http://ampgarage.com/forum/viewtopic.php?t=2858 AC does not change on start up with exception to a flicker...