[mrarroyo]

Yesterday I took delivery of a Singlepower MPX3 from tyrion (thanks Mike). It is a beautiful amp and it came w/ a wide assortment of tubes. Unfortunetly I do not know much about this amp and would appreciate assistance on tubes.

The amp was delivered with three (3) Slam Adapters, and two tube covers like the ones used in tube guitar amps by Fender. Furthermore it included the following tubes.

01. Two (2) black base Electro Harmonix 6SN7EH (matched)
02. One (1) black base Electro Harmonix 6SN7EH
03. One (1) brownish base Electro Harmonix 6SN7EH
04. One (1) black base w/ black tint Brimar 6SN7GT
05. One (1) light brown base Sylvania 6SN7WST
06. One (1) black base Rat Tel 6SN7GT
07. Two (2) black base Sovtek 6SN7GT
08. Two (2) JAN Phillips 5687
09. Two (2) JAN Sylvania 5687
10. One (1) EI 6CG7
11. One (1) RCA 6FQ7/6CG7
12. One (1) PhilipsECG 6CG7/6FQ7

I did a quick scan of threads dealing with the MPX3 and installed the two (2) matched black base Electro Harmonix 6SN7EH (see line 01. in the list above) in the middle and in the back tube sockets. I then installed the brownish base Electro Harmonix 6SN7EH (see line 03. in the list above) in the front socket.

So here are some of my questions.

1. Are the two back sockets the "power tube sockets" and thus by definition the front socket is the driver socket.?
2. Which are good combinations using the tubes listed above?
3. Should I hae all of the same type or should I mix and match 6CG7 with 6SN7, or with 5687?
4. Any specific tube or tube combo I should purchase?

Sorry for the noob questions but this is the first Singlepower amp I own. BTW, here are some pictures from tyrion's advertisement.

 

[n_maher]

Congrats on the great amp purchase.

As far as I know you're understanding the tube arrangement correctly, driver (input) in front, power (output) in the rear two. Mike's picture confirms that w/ a 6SN7 in the front and two 5687's at the back. I'd set it up with the tube combo from that first picture. I liked it that way very much.

 

[mrarroyo]

Thanks Nate, later when you have a chance shoot me a PM on the pre-amp feature and how it works.

 

[edisonwu]

1. Are the two back sockets the "power tube sockets" and thus by definition the front socket is the driver socket.? YES
2. Which are good combinations using the tubes listed above? We need your answer
3. Should I have all of the same type or should I mix and match 6CG7 with 6SN7, or with 5687? You're gonna play this on your own. Have fun.
4. Any specific tube or tube combo I should purchase? Let the SP GURU answer.

 

[tom hankins]

Of the tubes you have listed, I like the way the amp is set up in the picture you have posted the best. I would try and score a couple better (IMO) 6sn7s to run in front of your 5687s. TubeSeller.com-- Premium Tubes and Info gives some breif descriptions of many 6sn7s. My favorites are the KenRad VT-231 black glass, TungSol roundplate, sylvania 6sn7W Metal or black base tall bottle. Or the sylvania 1952 badboys. Great amp!!!!

 

[Dept_of_Alchemy]

Give the Tung-Sol 5687 a try, they're sort of the standard benchmark for how good 5687 should sound.

Congrats on the amp!

 

[purk]

Check out the Kenrad VT231 and the Tungsol 6SN7GT black glass. Your MPX3 should already sound very good with those stock tube, but it will sound a whole lot better with either of the above tubes in the driver position. You might want to check out some Tungsol D-getter 5687WBs for those output tubes.

 

[Tbln]

Congrats on your new toy!

Ken Rad + 2 X TungSol D-Getter 5687s bring a glow into my life.

 

[mrarroyo]

Last night I did a mini comparison of the three (3) Electro Harmonix 6SN7EH w/ the Brimar 6SN7GT in the driver w/ two (2) Jan Philip's 5687 on the output stage using the slam adapters (2). That combo did not work well for me!

Then I replaced the Brimar 6SN7GT with the light brown base Sylvania 6SN7WST in the driver position. Leaving the two (2) Jan Philip's 5687 on the output stage. IMO the sound improved a bit, being more musical and involving. The bass was deeper and wider, with the midrange more open, forward and sweeter. I still think the three (3) Electro Harmonix 6SN7EH sounded better but I will have to re-listen.

I shall continue the quest!

 

[cardude]

Congrats and enjoy!

 

[derekbmn]

As said earlier YOU NEED to get a hold of some Tung-Sol D getter 5687s. They really do sound MUCH better than the rest.(IMO) Used in conjunction with various Sylvania 6sn7s in the driver spot. The EH-6sn7s may sound impressive at first listen but over time their short comings will rear there head. The are very unrefined in comparison to the Sylvanias and better 6sn7s.
Here are some Tung-Sols-Matched Pair - 1957 TUNG-SOL 5687 tubes;Black P, 'D' - eBay (item 360018994502 end time Feb-29-08 13:28:11 PST)

 

[mrarroyo]

A few more questions before I blow up the amp!

1. Are all slam adapters equal? I got three and the look the same to me.
2. Can an slam adapter be used w/ a 5687 as a driver?
3. On what location do I use the tubes labeled 6FQ7 or 6CG7?

Thanks.

 

[guzziguy]

Quote:

Originally Posted by mrarroyo /img/forum/go_quote.gif A few more questions before I blow up the amp! 1. Are all slam adapters equal? I got three and the look the same to me. 2. Can an slam adapter be used w/ a 5687 as a driver? 3. On what location do I use the tubes labeled 6FQ7 or 6CG7? Thanks.

Hi Miguel,

No, all SP adapters are not equal. Mikhail sells a bunch of adapters. What I can remember off hand is that he sells the "Slam" adapters for the 5687 family of tubes, 7n7 adapters, 6cg7 adapters, ECC1 adapters, ECC2 adapters and 2c51 adapters. All except for the 5687 adapters are for the gain position. Usually the type is specified on the bottom of the adapter.

I suspect that you have two 5687 adapters and one 6cg7 adapter. If you were using the 6cg7 adapter with a 5687 tube when testing out the Slam setup, that might explain why you like the EH 6sn7's better. For me, the EH tubes sound very mediocre.

HTH.

 

[purk]

Quote:

Originally Posted by mrarroyo /img/forum/go_quote.gif A few more questions before I blow up the amp! 1. Are all slam adapters equal? I got three and the look the same to me. 2. Can an slam adapter be used w/ a 5687 as a driver? 3. On what location do I use the tubes labeled 6FQ7 or 6CG7? Thanks.

This is my respond to question #2. Yes, you can use the 5687 in the driver stage but from my the best experience with the slam tubes, they are at thier best when function as output tubes. I've used the TS D-getter on my SDS with the R10 in the past and discovered that I can hear some distortion with my R10.

 

[n_maher]

Quote:

Originally Posted by mrarroyo /img/forum/go_quote.gif A few more questions before I blow up the amp! 1. Are all slam adapters equal? I got three and the look the same to me.

If you look at the bottom of the adapters I tried to label the two that were definitely for the 5687's. It's faint, but you should be able to make it out.

And as far the preamp function goes it's always active when headphones are NOT plugged in. The headphone jack acts as a switch to disable the preamp outputs so that you can never have both active at the same time.