#1
So, last night I recently replaced my pre-amp tubes to Electro-harmonix 12ax7.

One of the tubes came in a package that all "crumpled", the box didn't look very secure, and didn't seem to stay closed too well.
The tube in that box had a few bent pins, but they were easily straightened.
Had a 5 second test to check the thing won't blow up. All works.

So, today I had a play, and I've noticed that the volume is significantly lower then it was before.
My initial guess is that the tube which was bent is damaged somehow - so later on today I'll replace it with the stock one. This is the tube slot to the far left if viewed from the back, "V1" according to the manual.

My amp does sound better, less harsh treble, whereas before the drive channel wasn't near as good, but reduced volume. I'm also wondering if a power amp tube may have ended up being damaged, but most likely the pre-amp.

So, I'll test the pre-amp later on.
But for now, is my diagnosis right?

EDIT: Would biasing my power tubes help get a nicer distortion?
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Quote by Doppelgänger
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Guitar:
- Ibanez S670FM w/ JB
- Fender 'Lite Ash' Stratocaster
- Fender '72 Deluxe Telecaster
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- Laney VC15

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Last edited by Simsimius at Jul 19, 2008,
#2
I heard that if a pre-amp tube doesn't work, the whole amp doesn't.
So it might be your power tube.
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#3
doesn't sound good but idk i think you got it right so far as for bypassing the power tubes i wouldn't but i also youldn't know if that worked either
#4
did you re-bias the valves?
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#5
Quote by lorrythebassguy
did you re-bias the valves?


I haven't changed the power amp valves, so no. But I think they might need biasing, as the sound is harsh. I hope there are nearby guitar stores that do this.

But I want to know if the pre-amp valve is definitely the problem. I read that a loss of volume means a pre-amp tube may be faulty, and tonight I will swap the possibly faulty one with a spare.
But I want to make sure I'm right and check all possibilities.
Sunn O))):
Quote by Doppelgänger
You could always just sleep beside your refrigerator.

Guitar:
- Ibanez S670FM w/ JB
- Fender 'Lite Ash' Stratocaster
- Fender '72 Deluxe Telecaster
- Arbiter LP Jr. Doublecut
Amp:
- Laney VC15

'72 Tele Appreciation Group
RIP DIO
#6
Quote by lorrythebassguy
did you re-bias the valves?
Not necessary.

TS... Did you change all of them? What to?

It's unlikely that the V1 valve is broken. If it sounds fine then it's fine. Swap them round in different places and see if the effects differ.

You can't rebias a Cathode biased amp.
The Laney Thread are big and clever. No exceptions.
#7
Quote by MrCarrot
Not necessary.

TS... Did you change all of them? What to?

It's unlikely that the V1 valve is broken. If it sounds fine then it's fine. Swap them round in different places and see if the effects differ.

You can't rebias a Cathode biased amp.


So I can't bias my power tubes? The how can I prevent the harsh tone?

I'll try and swap them around then.
All the channels are just really quiet, but the tone is improved, apart from the harshness of the power amp.
Sunn O))):
Quote by Doppelgänger
You could always just sleep beside your refrigerator.

Guitar:
- Ibanez S670FM w/ JB
- Fender 'Lite Ash' Stratocaster
- Fender '72 Deluxe Telecaster
- Arbiter LP Jr. Doublecut
Amp:
- Laney VC15

'72 Tele Appreciation Group
RIP DIO
#8
You can't bias them, no. It's not the poweramp causing the harshness.

It's just a common factor to most Laneys - especially when used at low volumes, they sound rather trebly. In band settings they're perfect, but down low it's often too much. Particularly with lots of OD.

If you do want to further decrease the treble, I recommend a speaker swap. It cured my VC30 of all the ice-pick, and transformed it into a roaring British beast of an amp.
The Laney Thread are big and clever. No exceptions.
#9
Quote by MrCarrot
You can't bias them, no. It's not the poweramp causing the harshness.

It's just a common factor to most Laneys - especially when used at low volumes, they sound rather trebly. In band settings they're perfect, but down low it's often too much. Particularly with lots of OD.

If you do want to further decrease the treble, I recommend a speaker swap. It cured my VC30 of all the ice-pick, and transformed it into a roaring British beast of an amp.


OK. I'm glad to know the power amp isn't going to a problem, and I've seen and heard many people say it's how they are designed, and I do like the sound if I want an Indie rhythm, but more often or not, I at least want a nice classic rock tone for rhythm and lead, especially as I love the amp as it.

I intend on changing the speaker at some point in the future, but I may buy an OD for the clean channel for when I want a bit more gain then the OD channel does naturally first, then get a speaker.
While I'm here posting, and recommendations for a speaker?
Preferably a 10" (obviously), but if necessary, I'll be happy to pay for a 1x (or 2x?)12" cab, and replace the stock speakers.
Sunn O))):
Quote by Doppelgänger
You could always just sleep beside your refrigerator.

Guitar:
- Ibanez S670FM w/ JB
- Fender 'Lite Ash' Stratocaster
- Fender '72 Deluxe Telecaster
- Arbiter LP Jr. Doublecut
Amp:
- Laney VC15

'72 Tele Appreciation Group
RIP DIO
#10
Quote by Simsimius
OK. I'm glad to know the power amp isn't going to a problem, and I've seen and heard many people say it's how they are designed, and I do like the sound if I want an Indie rhythm, but more often or not, I at least want a nice classic rock tone for rhythm and lead, especially as I love the amp as it.

I intend on changing the speaker at some point in the future, but I may buy an OD for the clean channel for when I want a bit more gain then the OD channel does naturally first, then get a speaker.
While I'm here posting, and recommendations for a speaker?
Preferably a 10" (obviously), but if necessary, I'll be happy to pay for a 1x (or 2x?)12" cab, and replace the stock speakers.
Instead of an OD pedal - I recommend an EQ. I have a Bad Monkey and I replaced it with a Danelectro Fish & Chips, and you can dial in any amount of boost you realistically want and control the tonality of the boost too - on top of the Drive channel, with a midhump and level boost, I get a brilliant old-school Metallica/Brown Sound tone.

As for the speaker, go for a replacement 10" for the amp. You've got two good choices - the Celestion G10 Greenback and the Eminence Ragin Cajun. The greenback would be better for British tones, Marshally rock tones, indie stuff. The Ragin Cajun would be smoother and better for cleans, but is also good at everything allround. Both brilliant speakers. Just a choice between British and American tone. I imagine the greenback would have smoother treble and warmer mids, and the RC would have a smooth characteristic allround the frequencies.
The Laney Thread are big and clever. No exceptions.
#11
Quote by MrCarrot
Instead of an OD pedal - I recommend an EQ. I have a Bad Monkey and I replaced it with a Danelectro Fish & Chips, and you can dial in any amount of boost you realistically want and control the tonality of the boost too - on top of the Drive channel, with a midhump and level boost, I get a brilliant old-school Metallica/Brown Sound tone.

As for the speaker, go for a replacement 10" for the amp. You've got two good choices - the Celestion G10 Greenback and the Eminence Ragin Cajun. The greenback would be better for British tones, Marshally rock tones, indie stuff. The Ragin Cajun would be smoother and better for cleans, but is also good at everything allround. Both brilliant speakers. Just a choice between British and American tone. I imagine the greenback would have smoother treble and warmer mids, and the RC would have a smooth characteristic allround the frequencies.


Ah ok. An EQ it is then.
The Celestion looks like a good bet, but I'll have a look on the net for as many soundclips as I can find of both speakers.

Thanks for the help.

EDIT: Is the dan true bypass?
Sunn O))):
Quote by Doppelgänger
You could always just sleep beside your refrigerator.

Guitar:
- Ibanez S670FM w/ JB
- Fender 'Lite Ash' Stratocaster
- Fender '72 Deluxe Telecaster
- Arbiter LP Jr. Doublecut
Amp:
- Laney VC15

'72 Tele Appreciation Group
RIP DIO
Last edited by Simsimius at Jul 19, 2008,
#12
Sorry for double post, but editing it won't bump it up with the new info.

It was a pre-amp tube in the V2 position. Replaced it with the stock TAD pre-amp. Volume restored.
It wasn't the tube that came in a damaged packet, but one that came in a perfect box. Appearances can be deceiving.
Sunn O))):
Quote by Doppelgänger
You could always just sleep beside your refrigerator.

Guitar:
- Ibanez S670FM w/ JB
- Fender 'Lite Ash' Stratocaster
- Fender '72 Deluxe Telecaster
- Arbiter LP Jr. Doublecut
Amp:
- Laney VC15

'72 Tele Appreciation Group
RIP DIO
#13
that sucks, can you send the faulty tube back?
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#14
Quote by chea_man
that sucks, can you send the faulty tube back?


I hope so.
I'll have to check the site or send an email.
Hopefully I can.
Sunn O))):
Quote by Doppelgänger
You could always just sleep beside your refrigerator.

Guitar:
- Ibanez S670FM w/ JB
- Fender 'Lite Ash' Stratocaster
- Fender '72 Deluxe Telecaster
- Arbiter LP Jr. Doublecut
Amp:
- Laney VC15

'72 Tele Appreciation Group
RIP DIO