6SN7 sub for 5670 in Monamours

[Altecboy]

Recently I bought a pair of 6SN7-to-5670 adapters from Garage1217 dot com.  $25 each.  Made in the USA.  Took about a week to get to me in NJ.

I must say this is a worthwhile experiment.  The gain is a bit less, but even with my passive preamp,  it plays plenty loud. 

To my ears the 6SN7 plays more refined than the stock 5670 tubes.  My speakers are Altec Model 19 clones and they play a bit hot in the upper midrange in my very live room with the stock tubes.  Much smoother with the 6SN7.  The imaging is improved as well. 

In my system, this was not a subtle change.

[Gerry E.]

Recently I bought a pair of 6SN7-to-5670 adapters from Garage1217 dot com.  $25 each.  Made in the USA.  Took about a week to get to me in NJ.  I must say this is a worthwhile experiment.  The gain is a bit less, but even with my passive preamp,  it plays plenty loud.  To my ears the 6SN7 plays more refined than the stock 5670 tubes.  My speakers are Altec Model 19 clones and they play a bit hot in the upper midrange in my very live room with the stock tubes.  Much smoother with the 6SN7.  The imaging is improved as well.  In my system, this was not a subtle change.

I'll add that this has been my exact experience too!  The Garage1217 adapters are the best I have come across and Jeremy is a great guy to deal with.  Also, I strongly prefer TS RP 6SN7s over any of the 5670 variants I have tried in my BH Paramounts (even with the lower gain, though I use an active line-stage). 

I occasionally try various 5670/396A types but always go back to 6SN7s due to their warmer, smoother and tonally dense sound.  BTW, I"m aware that somebody on the BH Forum posted the exact opposite conclusion, so there is plenty of room for differing opinions.  However, I think it's silly to make a definitive declaration.       

Gerry       

[Larpy]

That's interesting.  I've read that the 6SN7 doesn't swing enough voltage to properly drive a 300B.  Not true?

[Paul Birkeland]

The 6SN7 does have less gain, but that's not a limit to voltage swing.  The limit of voltage swing has to be analyzed in terms of the 6SN7 operating point and loadline.  I don't see any reason why you couldn't swing 250V RMS with a 6SN7, but you'd have to put a ton of signal into the grid to do that (15-ish volts at least), and that ends up being the issue.  In a modern HiFi system, there's generally such a ridiculous abundance of gain that having a power amp that's super insensitive may end up being a blessing at the end of the day, though we would tend to avoid selling one setup like that.

[johnsonad]

You know what's funny, I had the exact same experience with Model 19's.  I preferred the 6SN7  to the 5670 with that speaker.  With my current speakers, the 5670 is the clear winner to my ears.  It's nice to have more than one choice.

[Paul Joppa]

You know what's funny, I had the exact same experience with Model 19's.  I preferred the 6SN7  to the 5670 with that speaker.  With my current speakers, the 5670 is the clear winner to my ears.  It's nice to have more than one choice.

Now this is getting interesting! Would you describe your current speaker?

I have new 2A3 amplifiers (PB built them for me) with 6J5 drivers. They are still breaking in, but I think I like them so far, compared to my Paramounts. My speakers use JBL 15" woofers and horn tweeters, crossed at 800Hz - similar to the Altec Model 19 in that way.

[Altecboy]

Hello Aaron.  Which 6sn7's did you like the best?  I have tested NOS RCA, Sylvania.  And recent mfr. Sovtek, EH.  I like the RCA the best.  I needed to turn up the HF horns a bit for best balance. 

[Larpy]

The 6SN7 does have less gain, but that's not a limit to voltage swing.  The limit of voltage swing has to be analyzed in terms of the 6SN7 operating point and loadline.  I don't see any reason why you couldn't swing 250V RMS with a 6SN7, but you'd have to put a ton of signal into the grid to do that (15-ish volts at least), and that ends up being the issue.  In a modern HiFi system, there's generally such a ridiculous abundance of gain that having a power amp that's super insensitive may end up being a blessing at the end of the day, though we would tend to avoid selling one setup like that.

So would 6SN7s work as drivers in the Kaiju?  Using an adaptor without other modifications?

[Paul Joppa]

So would 6SN7s work as drivers in the Kaiju?  Using an adaptor without other modifications?

Yes. You would need to adjust the driver plate voltage, of course, but it should be within the available range of the trim pot.

[johnsonad]

Hello Aaron.  Which 6sn7's did you like the best?  I have tested NOS RCA, Sylvania.  And recent mfr. Sovtek, EH.  I like the RCA the best.  I needed to turn up the HF horns a bit for best balance.

What matters is what sounds best to your ears in your system.  With the 19’s I rolled a lot of different tubes and found something that worked for me at that time.  I moved houses and rolled tubes again as the room changed what frequencies were heightened and canceled. In short, tube rolling is based on the individual’s experience. What sounds good in your system might not sound great in mine.