The Amp Garage

What I was looking for was the blue to brown resistance, and the blue/white to brown/white resistance. Are you able to check the primary to secondary voltage ratios? eg if a measured low V AC is applied to the 4ohm secondary, what V AC is produced across blue to brown, and blue/white to brown/white...

bepone wrote: ↑Thu Feb 01, 2024 1:11 pm to throw all in scrap and reuse hardware? rebuilt some normal power amp..caps are too old now also

I measured the filter caps with my Peak ESR meter and they measured fine. As there are so many caps, I didn’t want to replace them unless I had to.

Hi PDF64 Good question, that’s the sort of thing I would be curious about. Given my curiosity I had to find out. I measured the transformers from the 6L6 tapping to the EL-34 tapping. On the first output transformer both side were 12 ohms. On the other transformer the measurements were 9.8 and 10.6 ...

Whilst looking up info on how this output stage works I came across this. https://www.ampbooks.com/mobile/classic-circuits/extended-a/ It harkens back to Randall’s days of patenting other people’s ideas. I don’t know why he thought that was a good idea. The real name is extended class A. I have come...

I have a Mesa Boogie 295 dual power amp to repair. IMG_1096.jpeg IMG_9252.jpeg It has an unusual story as the owner was going to throw it away and my brother took it. Oddly enough I never have this sort of luck. The EL-34’s are shot as you’d imagine, and a couple of the 12AX7’s are no good. I have n...

Did you carry out any mods to the guitar? Brass block etc. Only added a kill switch. After I received my Kiesel Delos with Floyd Rose, I realized the FR that came with the EVH is lower quality--the tuning machines are not as nice and smooth as Kiesel's German FR. I’m ignorant of Floyd Rose bridges,...

I bought this guitar (EVH Striped) last year, and have since put hundreds of hours in, practicing and playing more than a dozen gigs with my EVH tribute band, VanHagar. I have been very pleased. I changed the stock pickup to a Seymour Duncan, then back again to the original. The shielding has been ...

My son wanted his own guitar about a year ago and I got him one. He wanted a EVH guitar, he’s not a big fan of EVH, he liked the colour of the guitar, the fact it only has a bridge pickup and it can go into dropped D with the flick of a switch. He was a fan of Black Sabbath and I got him a Catanlynb...

I don’t have an insulation tester so is open an amp and solder an earth wire from the amp and a HT wire across the board and start measuring the eyelets.

https://ampgarage.com/forum/viewtopic.php?f=8&t=36597

I will try and keep the quality up.

What about the spider guitar strings. I was surprised that it broke so easily. It sounds alright.

The standard board material can become conductive, have you ruled that out as a possibility?

I rebuilt a Bassman 100 and I replaced the fibre board with a Garolite board as the original board was conductive.

The shielded cable was the game changer. It made the most difference. Which was the offending lead, or did you replace more than one? The usual culprit, the wire from the wiper of the volume pot. This wire would normally be on my hit list, but I thought the builder was on top of this. Everyone make...

R.G. wrote: ↑Wed Jan 03, 2024 2:58 pm

Mark wrote: ↑Wed Jan 03, 2024 7:29 am I think I’m nearly there. The noise on the output jacks is 10mV.

That's great! Good work. Can you tell us what worked best for reducing the noise?

The shielded cable was the game changer. It made the most difference.

I think I’m nearly there. The noise on the output jacks is 10mV.

Thanks for your help, your insight and your patience.
Much appreciated.