Tube Amp Archive

johnny99, Please be sure to post the solution/error when and if you find it Well, I'm happy to say that this problem is now fixed! The only solution I could come to was to remove the entire circuit board and rewire everything. It took a few hours, but it also allowed me to upgrade the Weber supplie...

The DC resistances you measured at the high and low inputs jacks are correct, so I am betting the input jacks are wired correctly. I think the next thing I'd do is measure the DC resistance from V1 cathodes to ground. This should be 820 ohms. Are you using active pups? If so, is your battery fresh?...

Your plate voltages look reasonable. I have more questions: Have you double checked the input jack wiring? In particular, are the 1M resistors present and properly wired? Are you using a guitar with active pickups? You said you noticed the scratchy pots when "you finally had a chance to crank it". ...

168V and 163V respectively on Pin 1 and 6.

Here's a diagram of all the voltages:

JazzGuitarGimp wrote:What's the plate voltage on the first stage of each channel? Did you install a vvr in this amp?

No VVR. I'll measure the plate voltages and report back.

Hey guys, I recently finished up a Weber 5E3 build. Pretty simple, works great. But today I finally had a chance to crank it and noticed that the guitar's volume pots were extremely scratchy. I tried the guitar on another amp and the pots were silent. So I have it back on the bench right now, and I'...

This spec sheet for a DR replacement PT, rated 330-0-330 at 120 mA, shows voltages for different rectifiers at two DC current levels: http://www.classictone.net/40-18016.pdf Thanks Martin, those voltages are way more reasonable. Maybe I'm paranoid, but running such high B+ has me worried that the 6...

Hey guys, I have a SF Deluxe Reverb, converted to BF schematic. But I've left the 5U4GB rectifier in place, since I was told that the SF PT is different and outputs too much voltage for use with a GZ34. That seems legit, since I'm already getting a very high B+ of 456V, so blindly changing the recti...

Hey guys, I have a 5E3 clone here that makes a pretty weird buzzing noise when playing at high volumes with the low E string. I know that's a pretty common problems with 5E3's, but this amp never buzzed previously. It almost sounds like the speaker coil is rubbing, but that has been eliminated as a ...

You need to get those mfs out and replace them with cc for starters, really. Just shot gun all of them and be done w/ it. If still too hard or bright then: Neither 6PS or 150s are right in old Fenders but maybe you'd be better off w/ 150s, they are a bit less clear. No idea if sozos or jupiters can...

Very cool!

Can you explain to me the "Floating Ground" that you have for B+1 and V2's cathode bias?

What speaker are you using, i find a 20-25 watt speaker to be much brighter than a 50-100 watt and regardless of amp i try to use at least a 50 watt speaker. Just seem warmer to me. Hi pops, I'm using a Jenson Falcon ( http://www.jensentone.com/jet_series/falcon_12 ). 50W ceramic with possibly a he...

If removing the 47pF bright cap helps but the amp is too bright and edgy on the trem channel (and the normal channel is better in that regard) then removing the 10pF bright cap may be beneficial. I can see that the original design intent of the 10pF cap may have been to compensate for the treble lo...

Hi guys, I just wanted to update on this thread. I'm using an original BF amp, not a reissue. It was originally a silverface that someone messed up trying to mod it, so I rebuilt it to AB763 using orange-drop caps and metal film resistors. The small capacitors are silver mica (including the 10pF at ...

Hey guys, I have a 10" Alnico Jensen with a 1CM long tear near on the surround area. I've searched a bit on the internet and got some different opinions about what glue to use, some suggesting wood glue, white school glue, super glue, gasket making silicone, etc (gotta love the internet). Some peopl...