Author Topic: Groove Tubes performance rating system  (Read 3610 times)

jrebman

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Groove Tubes performance rating system
« on: October 06, 2007, 04:58:13 PM »
Rich,

Got a quick tube question for you -- on the Groove Tubes, do you want a higher or lower number for hi-fi use?  I can't remember whether it is the things closer to a 10 or to 1 that you want for audiophile use.

I see they are coming out with a "gold series" of EL 84s, EL34s, and KT-88s among others -- looks interesting.

-- Jim
« Last Edit: October 06, 2007, 06:14:38 PM by richidoo »

Offline richidoo

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Re: Groove Tubes performance rating system
« Reply #1 on: October 06, 2007, 06:14:18 PM »
Created a new topic :)

Scroll down to "Groove Tubes rating system" here:
http://www.guitaramplifierblueprinting.com/groovetubes.html
for detailed explanation. Basically it is a distortion scale for use by electric guitar players who are their primary customers.  The lowest number will supposedly distort sooner than higher numbers.

I was pretty pissed at first when I looked at the performance ratings of the stock tubes on my Snappers. They were all in the low end, 1 to 4, for all 8 tubes. I was thinking they were distorting, and causing the mysterious "shouting sound" that I was hunting way back when. But whatever metric Manley is using to match tubes, these tubes are perfect for these amps. I can hear no problems at all. I would not hesitate to buy another set from them using same screening process. I just mention this to prevent you from thinking  a 'performance rating system' tube with number 10 is a better hifi tube than a 1. In hifi we hardly ever enter the part of the power band where distortion is grossly audible. Guitarists prefer to live there permanently (right?? :)  ), so the rating system is exclusively directly at them, I think. There may be something good about the sound or performance of a lower rated tube when used at low power levels to make it preferable in a hifi amp. Either that or it is just coincidence that mine are all in the low range. You could ask Manley tech support for more info. The tech guy (Paul?) is very responsive and helpful, even before I was a customer.

jrebman

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Re: Groove Tubes performance rating system
« Reply #2 on: October 23, 2007, 12:06:22 PM »
Rich,

Just seeing this now -- guess when the topic got split I didn't get notified.

Anyway, thanks, I'll call Manley Tech support and see what they say.  Apparently the 12ax7s are thought of as being pretty good for the Minimax phono stage -- for the outputs anyway.  Still want something special with exceptional triode balance for the gain tube.  I might even consider using a 5751 -- I have a few of those around and there's no harm in trying.

-- Jim

Offline richidoo

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Re: Groove Tubes performance rating system
« Reply #3 on: October 23, 2007, 03:22:38 PM »
Good to know, I will split the topic first, then respond. Then I think the response will appear in the new posts list.

Here's Manley's tech support info:

Paul Fargo, Technical Support
Manley Labs Service Center
1419 E. Sierra Vista dr. Globe, AZ 85501
TEL: (928) 425-9333 FAX: (928) 425-9787
<http://www.manleylabs.com>
<mailto:service@manleylabs.com>

At RMAF a Manley factory rep (don't remember who) said they are not using GT tubes in the Snapper now, I encouraged them to use them, but whatever reason, blablabla. He was unaware that Mitch Margoles designed the Groove Tubes E34Ls. He seemed relieved that he was "not with the company anymore..." My interpretation, that's all. So I don't know what the deal is with Manley/Groove Tubes nowadays.