help! amp deal gone bad (VHT content)

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stratotone

stratotone

Active member
I sold my '92 classic to a guy, and pulled the tubes before shipping. Amp arrived in perfect shape - he even sent me a text stating how well the amp was packed.

When retubing it, he put a 12ax7 in the driver position and told me how 'weird' the amp sounded. Over the phone I made sure he put the 12au7 in the proper spot (V6) and the amp has lost a lot of volume. He also swapped out all the preamp tubes (and put a 12at7 in place of the 12au7, NOT on my recommendation). BTW, the amp has the tube names and locations printed ON THE CHASSIS.

Question: could this have damaged the amp? He wanted a refund (which I gave) on the amp and is shipping it back, but the amp had ZERO problems when I shipped it, was packed like a brick shithouse and it just amazes me that the amp could have problems out of nowhere like this. I've looked online and have seen some dire warnings about not using a 12au7, but wanted 'rig-talk confirmation' because I trust you guys. And yes, I posted on vhtusers.com, but sometimes it takes awhile to get a reply.

Symptoms he had included low gain and volume on all channels. Once I get the amp back I'm giving it a good once-over and may take it to a shop if I see the same symptoms. What a pain in the ass!

Pete
 
Lame...

Either he messed things up by not listening to you in the first place, or he decided he didn't like it and played it off to get his money back. Props to you for being such a cool seller, but I hope the amp is ok for your sake!

Eric
 
I know on some amps, only certain preamp tubes can go in certain spots or the tubes will go bad or go half power. I just had that problem recently. Did he try switching out the preamp tubes before he sent it back? :confused: That may have been the problem, hopefully it was that and not anything worse.
 
Kudos to you Dawg, the karma kings will take care of you for sure...

I think the Buyer is a weirdo for messin' with proper instructions. Was he a kid or something??

V.
 
He wasn't a kid, just didn't pay attention to the chassis and I didn't think I'd need to give that detailed of an instruction set. We'll see how it goes. I offered to pay to have the amp checked out by a tech of his choice, and if the fix was inexpensive I would eat it to avoid having to have it shipped back. If the amp needed a more expensive (ie more expensive than I was willing to pay repair) then I would take the amp back.

He agreed to take it to his tech then called back an hour or so later and changed his mind - wanted a refund. I gave it to him via paypal and he's shipping the amp back tomorrow. He handled things differently than I would have in his shoes, but we'll see how it goes. My guess is it's a tube issue.

Pete
 
ibanez4life SZ!":18tqnp20 said:
Lame...

Either he messed things up by not listening to you in the first place, or he decided he didn't like it and played it off to get his money back. Props to you for being such a cool seller, but I hope the amp is ok for your sake!

Eric
Click to expand...
:thumbsup: :yes:
 
The 12ax7 or at7 should not hurt that amp at all.
It was designed to run any of them. The at7 and ax7 only give the amp more gain than it already has.

A friend of mine owns an original issue Pittbull 100 and he has run all of the above. I prefered it with the au7 myself though. It already has freight train gain with that tube in place.

Gary
 
This is what had me somewhat concerned... a VHT spec sheet for the Classic tube setup:

TUBE FUNCTION AND LOCATION CHART
PITTBULL CLASSIC HEAD
MODEL NUMBER ON CHASSIS IS G-100-CL
BUT IS NOT THE SAME AS THE HUNDRED/CL
Each 12AX7 has two sections/functions. Section A is shown first, Section B is second.
Factory recommended tubes are listed under each location. Numbering sequence is right
to left looking at back of amp starting with the row closest to front panel of amp.
V1 (shielded tube) Input Gain Stage 1 and signal splitter for all 3 channels
12AX7WB Sovtek
V2 Gain Stage 2 for Lead channel.
12AX7 China Gain Stage 3 for Lead and Rhythm channels.
V3 Gain Stage 4 for Lead channel.
12AX7 China Tone Control Driver for Lead and Rhythm channels.
V4 Gain Stage 2 for Clean channel.
12AX7 China Gain Stage 2 for Rhythm channel.
V5 Phase Inverter
12AX7 China
V6 Voltage Amp/Driver
12AU7 China
V7-10 Power Tubes.
EL34 Svetlana
IMPORTANT NOTE
PHASE INVERTER V5 AND VOLTAGE AMPLIFIER TUBE V6 ARE
NOT INTERCHANGEABLE WITH OTHER TYPES.
 
You can't hurt the amp by putting a lower or higher gain tube where it shouldn't be. It will just make it sound really bad, but not hurt it.
 
Sounds to me like the buyer kind of panicked. Probably a tube went bad but sometimes when a tube goes bad it can fry a resistor and make the amp go half power or clean when it should have overdrive. He didnt have patience and maybe replace it with other known good preamp tubes to troubleshoot, he just imediately tripped out and thought it was broken. whenever you take all the tubes out and ship it and replace all the tubes something can crap out like a preamp tube . even just taking all the preamp tubes out and putting them back in might have solved his problem after first noticing the problem. you gotta have patience with these things and do some poking around, not just freak out. kudos to you for being cool about it.
 
This is why I don't remove tubes when shipping an amp. Manufacturers don't ship amps that way. We rarely get anything shipped in with tube damage.

It never ceases to amaze me how people can't follow directions, have no troubleshooting skills, can't figure out how to set their amp etc.... :confused: How do they function in life??

Did the guy plug into the correct speaker jack?
 
stratotone":1r5kkiej said:
He agreed to take it to his tech then called back an hour or so later and changed his mind - wanted a refund. I gave it to him via paypal and he's shipping the amp back tomorrow. He handled things differently than I would have in his shoes, but we'll see how it goes. My guess is it's a tube issue.

Pete
Click to expand...
I would have waited til I got the amp back to refund his money. Hope all works out well.
 
Incredible. I owned this amp for the last 8 years completely trouble free. Hope it works out for you Pete.
 
I would have waited to take delivery o the amp BEFORE issuing a refund. You have no idea if he's a douche nozzle or not at this juncture but certainly sounds like he could be one. Perhaps he's just not liking it and making up shit to cover buyers remorse? VHT isnt for everyone, especially sloppy players as its hard to mask bad player technique, at least on the 50 CL :)

Email Steve or crew and they'll help answer you. They did back when I had reverb and tube questions when I got my 50 cl few years back.
 
I did a refund before getting the amp because he seemed like a pretty cool guy. I figured since he sent me the $ before I sent the amp, I could do the same on the refund.

*update*

Woke up to this in my email -

he checked the tubes again and V1 wasn't seated correctly. Sent me the money again and is keeping the amp.

It's been a weird deal, but works for me. I was just worried about all the warnings VHT put on that driver tube in all the literature I could find... but all's well that ends well!

Pete
 
Greazygeo":3cwy0sr6 said:
This is why I don't remove tubes when shipping an amp. Manufacturers don't ship amps that way. We rarely get anything shipped in with tube damage.

It never ceases to amaze me how people can't follow directions, have no troubleshooting skills, can't figure out how to set their amp etc.... :confused: How do they function in life??

Did the guy plug into the correct speaker jack?
Click to expand...

Last amp I shipped with tubes installed was full of glass by the time it got to the purchaser and while I didn't mind paying for new tubes, I felt bad for the guy who had to pull power tubes out by the bases. Heck, I sent a Mesa .50+ to Boogie back in the 90s for repairs and it came back in a really well packed box - with all the EL84s and preamp tubes shattered.

Since it did end up being a tube issue, I probably should have left em in there and packed around the tubes so they couldn't move. Live and learn, I'm glad it all worked out. I feel like an idiot about the driver tube thing, but Freyette/VHT was almost spooky in their admonishment to not use any other tubes. Just saying "Don't use other tubes, it will sound like crap" is better than "NEVER USE ANY TUBE BUT A 12AU7 IN THIS POSITION" :)

Pete
 
the thing is that the 12au7 or that 12at7 in the v6 of the fryette amps aren't a gain stage driver. The v5/v6 together act like how a phase inverter would act in any other amp. The gain factor isn't the issue. It's the tranconductance. A 12au7/12at7 has lower gain then a 12ax7 but has a much higher transconductance factor. Together the v5/v6 form the gain drive and conductance drive function of the P.I.
 
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