new build 36lite with vvr

[Bieworm]

Thanks bieworm,

With hindsight I should have built am 18 watt and tweaked for more headroom but here I am...

Seems to me all the post PI MVs are doing is cutting the signal, and therefore there overdrive, to the power tubes. And that's where the interesting stuff happens...

Having said that I'd love to hear from someone who has built the 36w lite, break up on mine is a lot later than the 18 I built and definitely significantly less distortion available overall.

Just played the amp again this morning. It's a glassy rattle in the treble, only with the volume up near half so with slight breakup and more noticeable on certain notes, it almost sounds like a rattly tube or something. Now I think of it I'll tighten all the nuts and bolts...

Hey... there's a "hear it" section in the forums link. There are a lot of soundclips there from various posts.

For example:
viewtopic.php?t=21354
viewtopic.php?t=19618

Here's a link to my 36W tremolo TMB... overdrive for days!
viewtopic.php?t=25859&hilit=tremolo+tmb&start=105

[chaliapin]

Mine sounds similar to the second of the three but no one tells you what volume setting they're using!

[Bieworm]

Mine sounds similar to the second of the three but no one tells you what volume setting they're using!

I don't know what the volume settings on the first 2 amps is, but mine was set at 8 or so

[chaliapin]

I could tell yours was cranked! Ha ha! Your circuit has an extra gain in the preamp though doesn't it? Im more into colourful dirt than raunchy rock tones, I'd just like to know it's working right...

[Bieworm]

a lot of the way your amp presents itself when it comes to dirt is the way it's biased and the B+ voltage. It's a matter of balance... and yes , the tremolo TMB has some delicious preamp dirt, more than the Lite for that matter.

The 'break wind' attenuator could be interesting for your purposes...

[chaliapin]

Have you built one bieworm? Where did you get parts? You're in Europe aren't you?

[Bieworm]

I’m from Belgium, yes. No I haven’t built one for there’s no need for me to have one.. yet
I source my parts from tubetown and jukeboxrevival.nl. The latter will probably supply most required parts

[JMPGuitars]

With hindsight I should have built am 18 watt and tweaked for more headroom but here I am...

What's stopping you from removing 2 of the tubes and rebiasing it for 18W? If that's what you really want, then do it. Cover two of the sockets with some masking tape so you know not to use them.

[chaliapin]

I may end up doing that Josh but I really want to get it working properly as 36watt. The nasty noise got worse after my last attempt at soldering improvement... im planning on working on all the joints then posting more pictures so you guys can hopefully tell me which are the worst...

What all I aiming for on the valve sockets solder joint wise?

I understand the irony and futility of amplifying an acoustically quiet electric guitar to wonderful, roaring, ear splitting levels... then putting a lot of effort into making it quieter again...

[JMPGuitars]

I may end up doing that Josh but I really want to get it working properly as 36watt. The nasty noise got worse after my last attempt at soldering improvement... im planning on working on all the joints then posting more pictures so you guys can hopefully tell me which are the worst...

What all I aiming for on the valve sockets solder joint wise?

I understand the irony and futility of amplifying an acoustically quiet electric guitar to wonderful, roaring, ear splitting levels... then putting a lot of effort into making it quieter again...

If that's what's happening when you try to improve the solder, I think we need to pause for a moment. What equipment are you using for soldering? What kind of solder? What temperature are you soldering at?

Forget your amp for a moment, and practice soldering like the videos. Work out the heat bridge and see it melt every time before you paint the solder on. If you have something to practice on besides the amp, that would be ideal.

[chaliapin]

Im not sure what's up with my soldering, I'm applying the iron, waiting for the bridge to flow, painting, removing solder, removing iron. Joint looks lovely solidifying then at the last second goes hazy. Eugh. 25w EDIT ANTEX iron, silverline cheap 60/40 solder.

Anyway, before I read your message Josh i was trying to improve joints. Basically removing excess solder then reflowing with a little fresh solder. Powered up to check my grid voltages, one pair very low, brilliant, one pair not. Anyway left the amp on a few minutes and came back to an unpleasant noise and burning smell. Powered off fast before I could see what was happening. No visible or smellable problems anywhere.

Used the bulb limiter, voltages roughly halved all over the amp except v2 - pin 1 and seven fine but the rest less than 5v. Switched tubes, same story. Powered up to the mains anyway, all voltages fine, no buzzy noise, no burning smell. Still a nasty glassy sound in the treble basically same as it's been for days. Worse at higher volume.

Ive chopsticked fairly firmly every single turret, socket pin and wire looking for a crackle of a cold joint. Nothing.

I know I need to post pictures and a recording of the noise.

Getting fed up. Thanks for your patience.

[chaliapin]

I also meant to say that c5 is a little microphonic, the 22n cap going to the grid of the PI (coupling cap?) I assumed that was simply because it's on the grid pin and sensitive. I don't have a spare cap of the correct value to try replacing it.

[Bieworm]

I also meant to say that c5 is a little microphonic, the 22n cap going to the grid of the PI (coupling cap?) I assumed that was simply because it's on the grid pin and sensitive. I don't have a spare cap of the correct value to try replacing it.

There are caps and resistors in the signal path that make noise when you tap them. That's nothing to worry about.

[JMPGuitars]

That iron should be good enough, but maybe you should try some better Kester solder.

You might also want to check on your 470p cap going to the tone control.

[chaliapin]

Power tube grid acting strangely. Got them down to 0.03 or so volts but after a few minutes one pair is climbing to over 1 volt. Resistors measure as they should to ground,
i replacedsome wires to the pin sockets. what's going on and is it important? I'll try to attach pictures of the joints

[chaliapin]

The turret joining the two resistors but messy as I had the MV wires soldered onto the tops.

[JMPGuitars]

Components should not be touching each other at all. The soldering could be a lot prettier, but make sure you separate everything physically too.

[chaliapin]

It's just the camera angle. Think my caps are leaking DC?

[JMPGuitars]

weirdcap.jpg

What's going on with this cap's connections? Are they wrapped around the turret and the camera angle is weird? Or is this weird on its own?

[chaliapin]

The legs go down vertically then wrap around the turret. They are rated 400v, I have two others rated 600 which I am going to put in their place, I was getting intermittent short through one of them. Im really hoping this is the problem ive been looking for.