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What pre amp tube for SWR?

Nephilymbass

Nephilymbass

Feb 7, 2011
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Fayetteville/ Ft Bragg, NC
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#1
So I have my trusty old SWR head that's been sitting in the corner of the rehearsal studio for a while. As I got tired of its super clean sound for my rock/metal band and its a bit heavy to be used as a power amp. But were talking about doing a concept album where with acoustic guitars and fretless bass. So Im wanting to use it for recording that in the winter. Thing is I'm not digging the sound of it and it doesn't sound like it used to after replacing the original pre amp tube with a groove tools. Any help on what tube to get to get sounding closer to it was originally?
 
#3
Nephilymbass said:
So I have my trusty old SWR head that's been sitting in the corner of the rehearsal studio for a while. As I got tired of its super clean sound for my rock/metal band and its a bit heavy to be used as a power amp. But were talking about doing a concept album where with acoustic guitars and fretless bass. So Im wanting to use it for recording that in the winter. Thing is I'm not digging the sound of it and it doesn't sound like it used to after replacing the original pre amp tube with a groove tools. Any help on what tube to get to get sounding closer to it was originally?
Click to expand...

Not too sure anymore, but the Groove Tubes used to come in 2 versions, US and China (maybe it was Russia and China), anyway I don't think you want the Chinese version.
 
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#10
I have an SM400 and this amp is NOT sensitive to tube rolling.
Have tried original Telefunkens, Mullards, Amperex, as well as some new tubes and the difference in tone is minimal.
Sorry about that…
They are not hard on the pre-amp tube so a quality tube will last years at normal use.
 
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#14
I'm trying different tubes in my 350 at the moment.It came with a JJ which I swapped for a EHX.I recently put a Mesa/Boogie SPAX7 special requirement tube.I dont really know what special requirements means but it sounds great.I ordered a Tung-Sol and a Telefunken that should be here this week.I think I'm going to try one of the tubestore 12ax7 mentioned above.
 
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#16
Nephilymbass said:
The amp I'm referring to is a 750x pre fender.
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My SWR is an early unit long before Steve even thought about selling to Fender.
I have read on this board (by someone far more educated about electronics than I) that the tube is in a gain stage but is not really there to impart much of a tube tone.
My SVT 3Pro had zero difference even when swapping many tubes; same with the 7 Pro, very minimal change.
The Walkabout as well as many all tube amps do benefit from a good tube in the V1 position.
BTW, the Telefunkes I'm referring to are form the 60's and were made in Germany. They sell used for $40-65 ea.
As I understand it, the repros are not made from the same materials and not sure about the quality control.
BTW, we are talking about subtle differences. Changing one working single tube preamp with another good working tube is not like changing amps.
IMO/IME
 
#17
Jim C said:
My SWR is an early unit long before Steve even thought about selling to Fender.
I have read on this board (by someone far more educated about electronics than I) that the tube is in a gain stage but is not really there to impart much of a tube tone.
My SVT 3Pro had zero difference even when swapping many tubes; same with the 7 Pro, very minimal change.
The Walkabout as well as many all tube amps do benefit from a good tube in the V1 position.
BTW, the Telefunkes I'm referring to are form the 60's and were made in Germany. They sell used for $40-65 ea.
As I understand it, the repros are not made from the same materials and not sure about the quality control.
BTW, we are talking about subtle differences. Changing one working single tube preamp with another good working tube is not like changing amps.
IMO/IME
Click to expand...

Yeah I'm starting to wonder if there's possibly something wrong with the amp. But to me there is a noticible difference. Maybe I'll just have it looked at, fixed if need be, and sell it.
 
#18
If you want some difference, a "softer" sound, a little more mids less highs... I recommend a Philips miniwatt ECC83, if you can find a long plate you'll be amazed, I've one on a SM 900 and the difference with the 12ax7EH is huge, the negative is it was around 70€ but Worth it ;)

P.S.: I play a fretless 90% of the time!
 
#20
davideuck said:
If you want some difference, a "softer" sound, a little more mids less highs... I recommend a Philips miniwatt ECC83, if you can find a long plate you'll be amazed, I've one on a SM 900 and the difference with the 12ax7EH is huge, the negative is it was around 70€ but Worth it ;)

P.S.: I play a fretless 90% of the time!
Click to expand...
This. I have one of these in my Science Hellhawk. Bass or guitar, no other tubes shine as much as the Philips does in my first position. However buying these tubes through a reputable vendor is pricey and going eBay or Craigslist can be a crapshoot. And it is really hard to say if you'll hear a tonal difference swapping the pre-amp tube based on the amp's design. So my advice is to get a JJ and a Tung-Sol. Both are cheap, high gain, one is brighter while the other is darker.
 

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