Amp Tech Thread / Ask a tech Q

mortlock · June 10, 2014, 12:32:10 AM

can I safely plug a bass with a distortion pedal into one input on my bass head [peavey mark 6] and a synth into the other input and run them together through an ampeg 410..

VOLVO))) · June 10, 2014, 09:30:21 AM

Yeah, just be mindful of how low the synth goes.

RacerX · June 22, 2014, 01:13:37 PM

Verellen gets some hometown press:

http://seattletimes.com/html/entertainment/2023871080_madeinseattle01xml.html

Danny G · July 02, 2014, 10:20:52 AM

Will be pulling apart my SVT in the next day or two.

Has developed a hum. Finally checked the bias last night before using it and bias way off, 32 instead of 72 k1 to ground. Got it where it should be but hum still there.

Hopefully it's a preamp tube going. But I know the power tubes are 3 years old and I've used the hell out of them.

Sent from a can on some string using Tapatalk

Lumpy · July 16, 2014, 03:43:39 AM

Question: I was using my 100 watt toobz bass amp, and trying to get all the volume possible from it. Somewhere between 9:00 and 10:00, the amp doesn't get any louder after that, or so it seems (only gets more distorted... which I'm told is normal). But when I was testing the limits in the zone there (and doing some EQ tweaking) I started to get a faint but noticeable chorus or phasey sound in the higher frequencies. Is that normal? This was during a show. Trying to make a pony seem like a Clydesdale or whatever metaphor. What happened?

RacerX · July 16, 2014, 05:58:33 PM

This may not be the correct answer, but with my Mesa guitar amp, a lot of harmonic overtones appear as I increase the volume into power tube distortion territory. The compression effect also continues to increase as the volume goes up, so it could also have to do with that. Then there's speaker distortion, which can make some really weird sounds...

Pissy · July 16, 2014, 06:54:55 PM

Microphonic toobz do strange things like this. Can you do a pull, swap test with some other tubes? Perhaps try and single one out?

I play a 120 watt tube head with bass and stay right there at the cusp as well. I use a vol pedal get into saturation territory, so live I'll run it at 1:00 while at practice it'll be about 11:00.

VOLVO))) · July 16, 2014, 06:58:35 PM

I use my 800 for bass. Not much for clean tones but microphonic preamp tubes have done similar to me in the past

Jake · July 16, 2014, 09:29:19 PM

I just popped in a new quad of 6L6s in my amp and one glows noticeably blue, whereas the others do not. Anyone know what the issue might be?

VOLVO))) · July 16, 2014, 09:35:18 PM

Funk tube, swap it to a different socket and see if it follows.

Jake · July 16, 2014, 09:36:57 PM

I will once it cool off a bit. In the meantime, I stumbled onto this and don't feel quite so anxious...

http://www.thetubestore.com/Blue-Glow

Lumpy · July 17, 2014, 12:36:36 AM

Quote from: RacerX on July 16, 2014, 05:58:33 PM
This may not be the correct answer, but with my Mesa guitar amp, a lot of harmonic overtones appear as I increase the volume into power tube distortion territory. The compression effect also continues to increase as the volume goes up, so it could also have to do with that. Then there's speaker distortion, which can make some really weird sounds...

Seems like my experience. No problems while working hard, it was only until going past "useful volume" and the overtones could be described as "swirly" harmonics. I don't think it was speaker related, although half of my speakers are 70s vintage (Ampeg 8x10).

BTW, I was next to the amp, the audience might not have noticed it at all, I dunno.

Danny G · July 17, 2014, 11:34:33 AM

If it was noticeable I'm sure at least one person looked at your pedals to see what you were using to get that sound \m/,

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RacerX · July 17, 2014, 11:41:40 AM

Quote from: Jake on July 16, 2014, 09:36:57 PM
I will once it cool off a bit. In the meantime, I stumbled onto this and don't feel quite so anxious...

http://www.thetubestore.com/Blue-Glow

Thanks for that link.

Jake · July 17, 2014, 05:15:32 PM

Question for those who know more than me:

Could one run a Sunn Concert Slave with just a fuzz pedal (as the "preamp")? And if so, how much would it sound like shit? Or not?

dogfood · July 17, 2014, 11:49:41 PM

I would bank on that combo...personally. I have had two sunn concert leads and there is sumptin about them. I still have one of them and will die before I part ways with 'er.

spookstrickland · August 18, 2014, 08:05:42 PM

Quote from: Jake on July 17, 2014, 05:15:32 PM
Question for those who know more than me:

Could one run a Sunn Concert Slave with just a fuzz pedal (as the "preamp")? And if so, how much would it sound like shit? Or not?

Probably if it had enough volume boost. I once ran a car stereo amp and cabinet with a little booster pedal I made...sounded pretty heavy!

Lumpy · August 21, 2014, 01:47:16 PM

In order to straighten out the neck of my Squier, I had to tighten the truss rod basically all the way. Now what? The neck is back on the body and it could stand to be even straighter (a little). What does this mean for the long term, etc? Can the neck be saved, etc?

VOLVO))) · August 21, 2014, 02:00:27 PM

You can loosen the TR, completely, and clamp it to something very flat, in the sun for a bit. I let mine sit for about a month.

Lumpy · August 21, 2014, 02:05:35 PM

Whoa. Okay, that's good news I guess (it can be fixed). But time consuming.

Jake · August 21, 2014, 02:10:57 PM

Have you tried putting a shim in the neck? It's super easy, and you can adjust the neck either way, depending on where you place the shim.

Plus, you only need a business card or something of about the same thickness.

The Shocker · August 21, 2014, 02:54:54 PM

I think Jakey had to shim the neck on my Squier Jag.

RacerX · August 21, 2014, 02:56:23 PM

What about adding a washer?

http://www.stewmac.com/How-To/Online_Resources/Truss_Rods/A_sign_of_truss_rod_trouble_and_an_easy_solution_.html

Danny G · August 22, 2014, 03:27:25 PM

Just had my SVT serviced for a retube, but also (finally) needed filter caps and apparently had a grounding issue and some other weird out-of-the-factory things.

About $500 worth of work altogether including the tubes which I ordered myself to save money.

Ouch. However, it's sounds amazing, other than the exhaust fan runs quiet as a mouse, and I shouldn't have to worry about the filter caps again until I, and the amp, are 80.

Pissy · August 24, 2014, 12:19:38 PM

Quote from: Danny G on August 22, 2014, 03:27:25 PM
Just had my SVT serviced for a retube, but also (finally) needed filter caps and apparently had a grounding issue and some other weird out-of-the-factory things.

About $500 worth of work altogether including the tubes which I ordered myself to save money.

Ouch. However, it's sounds amazing, other than the exhaust fan runs quiet as a mouse, and I shouldn't have to worry about the filter caps again until I, and the amp, are 80.

This is that SVT II rackmountable deal that you've had (and gave you fits) for some years now? The one that a buddy told you his had the same noisy problem?

It's finally in good working order?