Biasing Twin Reverb help.

[Chuck H]

Regarding the circuits in discussion, bias circuit and specifics on what might be connected to the output tube grids, PI circuit, NFB, etc... This is all very nebulous! Is it "balckfaced" entirely? Partially? What parts? What parts are not?

We don't have a schematic for this amp. (<period)

Further, the layout of the BF and SF circuits can differ greatly. And this amp may now be neither and both.?. We don't have an actual schematic and it's quite impossible at this point to have a comprehensive ground scheme outlined.

Odd noises of any kind should not be typical in use for an amp with a considered and tested circuit. That is NOT this amp at this point.

We have no idea what we're actually dealing with and you can't tell us. So where do we go from there...?

[Chuck H]

Hey, that last post is a bit snarky. I can admit this. No offense intended, it's just frustrating. So...

Any problems can be solved for even with vaguely defined circuits. But!!! You have to be willing to perform and report requested tests!!! No complaints about uncomfortable circumstances or feared reactions accepted. You've been here long enough to know the safety procedures or how to look them up so there are no concessions given. We will work hard to solve for any problems you have. But that will fail any time you demonstrate reticence about tests or fail to answer any test request in favor of a post that better suits your ideal. There are NO ideals at this point. Only troubleshooting. If you fail to accomodate ANY test request failure is probable and this thread will run several pages with no result. With no apologies or humility I will say that this is typical of your correspondances here. It doesn't have to be like that. We actually want you to have a working amp.

[DrGonz78]

I might have missed it earlier but where is the center tap for the high voltage supply grounded? In the picture I see it going somewhere but grounding it nearest first filter capacitor is best. Don’t know about heater center tap but if you have one grounded then don’t install virtual center taps. Hum balance pot would probably help. But yeah you need to roll up your sleeves and get some elbow grease action going on.

[Helmholtz]

To my understanding it's not clear if the amp still hums.
There's a good chance that the better matched tubes and/ or something the pro builder did, cured the problem.

[Justin Thomas]

To my understanding it's not clear if the amp still hums.

I think we're waiting to hear back from SeaChief on that.

Jusrin

[Helmholtz]

I might have missed it earlier but where is the center tap for the high voltage supply grounded? In the picture I see it going somewhere but grounding it nearest first filter capacitor is best. .

Pic shows 4 diodes in bridge configuration (as with the original amp), so no grounded CT.

[DrGonz78]

The thread is a bit confusing. Fire up that amp Sea Chief!

[Sea Chief]

Hey, that last post is a bit snarky. I can admit this. No offense intended, it's just frustrating. So...

Any problems can be solved for even with vaguely defined circuits. But!!! You have to be willing to perform and report requested tests!!! No complaints about uncomfortable circumstances or feared reactions accepted. You've been here long enough to know the safety procedures or how to look them up so there are no concessions given. We will work hard to solve for any problems you have. But that will fail any time you demonstrate reticence about tests or fail to answer any test request in favor of a post that better suits your ideal. There are NO ideals at this point. Only troubleshooting. If you fail to accomodate ANY test request failure is probable and this thread will run several pages with no result. With no apologies or humility I will say that this is typical of your correspondances here. It doesn't have to be like that. We actually want you to have a working amp.

The last post? Just that one-?

Fact is the amp worked perfectly, for 18 months.

I do not ask you guys about it, if it had -always- had noise problems. I ask you/ I have only ever asked you, once it became noisy.

You just encourage others to follow you (as is the case on forums.. the herd follow the bully) & you continually diss me/ my build/ my pro guy who designed the revamp/ & you now diss my pro builder whose gone over it too.

You must be better than both my pro builders then, would you say? I get strong anti-U.K vibes, Chuck.

---

SC

[Helmholtz]

Still hum??

[Sea Chief]

The thread is a bit confusing. Fire up that amp Sea Chief!

Hi Gonz.

Yup have been putting it off. It frightens me (& nerves are shredded by vile n'bour abuse at the moment too: a popping 80w Twin Reverb isn't fkn welcome: plus I certainly DON'T care for any additional stress by angry demeaning replies too).

Ok fired her up, & STILL get some noise. Goddam it.. can't believe it. The HUMM has thankfully fkd off. No HUMM it seems. Remedied. Good.

But some occasional intermittent noise is there. Enough to feel uncertain, wary, frankly occasionally scared, enough to eventually turn it off due to it. But there were periods of perfect quiet amp, & it sounded lovely. Then the 'interference' type noise starts, gets a bit worse, a few mild pops in there.. & this occurring a few times, & I switch off/ can't play feeling jittery can you.

I'll see if I can tie it with the reverb/ see if it happens on Normal channel, & other inputs, & Vibrato channel with reverb switched off. I did notice a few hairline cracks in one 6L6 socket too, so that's something I can swap out. But I'm really back to square 1, I say rather defeatedly now. Not told my pro chap- I just can't face it.

Thanks, SC

[Sea Chief]

Still hum??

No.. but (intermittant) noise still there. Detailed in post above HH.

Thanks, SC

[Chuck H]

The last post? Just that one-?

Fact is the amp worked perfectly, for 18 months.

I do not ask you guys about it, if it had -always- had noise problems. I ask you/ I have only ever asked you, once it became noisy.

You just encourage others to follow you (as is the case on forums.. the herd follow the bully) & you continually diss me/ my build/ my pro guy who designed the revamp/ & you now diss my pro builder whose gone over it too.

You must be better than both my pro builders then, would you say? I get strong anti-U.K vibes, Chuck.

---

SC

My best advice would be to tighten up what works for you consistently and keep to that. This amp / electronics stuff isn't your game and it's not advancing your life such that the juice is worth the squeeze to participate. Just find some mediocre amps with acceptible tone and play. Focus your inquiries on life affirming matters for you. These electronics ventures haven't worked out for you. I only hope to help by recognizing this.

Where is this anti UK vibe coming from me? This is just a you thing. And it might help if we weren't looking at an insane naked man sitting at his computer in your avatar. It's not avantgarde or cool. It's just disturbing.

Run with what you're good at. Make peace and prosperity in your life. You're not good at amps and their electronics. Let this part go. It would be best for you and us as well.

Peace out. Uncle Chuck.

[DrGonz78]

And it might help if we weren't looking at an insane naked man sitting at his computer in your avatar. It's not avantgarde or cool. It's just disturbing.

I think the avatar is pretty funny. But I am disturbed naturally.

[Chuck H]

I might be abraisive but I wasn't adversarial. Anti UK !?! Ok. So now I take my shots where the guard is down. Fine. This from the guy who's avatar use to be a dog butt in sunglasses

[Mick Bailey]

Anti-UK? I don't see that at all. Even if I squint and press my eye to one side until I see double, I still don't see it.