Sensitivty of V1
Moderators: pompeiisneaks, Colossal
Sensitivty of V1
Hey Folks,
Is it a common thing with Wrecks that V1 is EXTRA sensitive? The 2 liverpool type builds I have done are extremely sensitive in the V1 position. Almost every tube I stick in that position acts like it's microphonic when this is not observed in other amps with the same tube.
Any ideas as to why this is and how to fix the issue?
Is it a common thing with Wrecks that V1 is EXTRA sensitive? The 2 liverpool type builds I have done are extremely sensitive in the V1 position. Almost every tube I stick in that position acts like it's microphonic when this is not observed in other amps with the same tube.
Any ideas as to why this is and how to fix the issue?
Eardrums!!! We don't need no stinkin' eardrums!
Re: Sensitivty of V1
Yup, I went through a bunch tubes(most of which were pretty well
behaved in other amps) before finding something useable . Changing the grid wires from solid core to stranded pvc helped quiet things down too.
behaved in other amps) before finding something useable . Changing the grid wires from solid core to stranded pvc helped quiet things down too.
Re: Sensitivty of V1
Good tip. I like solid core for some obvious reasons. I'll make these changes tonight to see if that's the ticket.
Eardrums!!! We don't need no stinkin' eardrums!
Re: Sensitivty of V1
Then there's the sound condom. Always practice safe sound.
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A guitar should never sound like a bee, a duck or, a chainsaw (well sometimes a chainsaw is alright )
Re: Sensitivty of V1
shrink wrap and o-rings baby! Yeah!
Any ideas where the get metal like is inside that cab for vents?
Is that your amp?
Any ideas where the get metal like is inside that cab for vents?
Is that your amp?
Re: Sensitivty of V1
Maybe this is why Ken perferred different wire colorsdartanion wrote:Good tip. I like solid core for some obvious reasons. I'll make these changes tonight to see if that's the ticket.
Re: Sensitivty of V1
You can buy sheets of perforated aluminum from McMaster Carr. It's really cool stuff to use.
Re: Sensitivty of V1
Have you tried the Sovtek 12ax7LPS?
They're supposed to be quiet, but you know how claims go.
I'm on the same hunt and have some on the way to check out.
If not any audiophile type store has all kinds of things for tubes like coolers, dampners,etc. They're usually $$ though.
Good luck.
They're supposed to be quiet, but you know how claims go.
I'm on the same hunt and have some on the way to check out.
If not any audiophile type store has all kinds of things for tubes like coolers, dampners,etc. They're usually $$ though.
Good luck.
Re: Sensitivty of V1
If you want to save yourself a LOT of frustration by trying to find the "perfect" tube which is not microphonic, wire a 33k 1 watt resistor directly on to pin 7 of V1. It also kills any oscillations the amp may be having. The standard value for virtually every other amp on the planet is 68k but 33k seems to work just fine and does NOT suck the tone out of the amp ...
Just my 2 cents ....
More info can be found here:
http://www.aikenamps.com/
Go to TECH INFO then "Grid Resistors - Why Are They Used?"
Just my 2 cents ....
More info can be found here:
http://www.aikenamps.com/
Go to TECH INFO then "Grid Resistors - Why Are They Used?"
Re: Sensitivty of V1
I saw some here:jurgen wrote: Then there's the sound condom.
http://search.ebay.com/_W0QQsassZsandyphoto
Also, Viton o-rings are good to 400 degrees F. Ebay or auto stores.
Tim
In case the NSA is listening, KMA!
In case the NSA is listening, KMA!
Re: Sensitivty of V1
I've been struggling with microphonics in my Express build and I think it's coming from V1. Strange noise on the high end when the gain is 1/2 way up. I switched to a NOS GE 12AT7 and it fixed the issue. I also wanted less gain so the AT7 was what worked for me.
Omar
Omar
Tone by misadventure
Re: Sensitivty of V1
The type of shielded cable you use internally between the jack and V1 can also have a significant bearing. I found that by making a selection of 3ft leads with different types of cables and plugging them into the Express you can really hear just how astonishingly microphonic some cables are. Once you've found a nice, quiet, low-capacitance one substitute it in internally.
As a consequence of this experiment I'm also revoking my earlier recommendation for Sommer Onyx 2025 as it's all but unusable in an Express.
As a consequence of this experiment I'm also revoking my earlier recommendation for Sommer Onyx 2025 as it's all but unusable in an Express.
Re: Sensitivty of V1
Actually the standard value is usually 34K since the two 68Ks are in parrallel when plugged into the high input of a Marshall /Fender. It also reduces RFgcenker wrote:If you want to save yourself a LOT of frustration by trying to find the "perfect" tube which is not microphonic, wire a 33k 1 watt resistor directly on to pin 7 of V1. It also kills any oscillations the amp may be having. The standard value for virtually every other amp on the planet is 68k but 33k seems to work just fine and does NOT suck the tone out of the amp ...
Just my 2 cents ....
More info can be found here:
http://www.aikenamps.com/
Go to TECH INFO then "Grid Resistors - Why Are They Used?"
Re: Sensitivty of V1
I'll try the grid stopper on V1 and see if that helps first, then I start rewiring if need be. I didn't have time to get to it last night.
I'd really prefer to not use a condom
Bare back tubes for me
Talk about amp porn
I'd really prefer to not use a condom
Bare back tubes for me
Talk about amp porn
Eardrums!!! We don't need no stinkin' eardrums!
Re: Sensitivty of V1
Maybe you should tack a switch in there to switch on and off the 33K resistor to see if there is a difference. I usually go through a bunch of tubes to find the best sounding / least microphonic tube I can find. Ken reportedly went through dozens of tubes and spent up to a couple of weeks to tube an amp to his satisfaction.