[alex_cs]

Well after a decent amount of time and a few administrative ****ups, my MPX3 SLAM SE has arrived, in about 3 days real time from colorado to sydney no less!

Now I apologise if this seems like a help thread mainly, because i need some and Mikhail can be tough to contact, and has done more than enough.

Mikhail sent me 6 tubes, two are 5687's with nearly all of the red print on the glass worn off, i can also see RAND and some numbers like 42 and 80.

Also two westinghouse "reliatrons", both 6SN7 GT's, but both look different, one stamped "337 5R22" and the other "337 4R13"

An electro-harmonix 6SN7EH.

And a GE 6SN7 GTB.

Now dont abuse me if Ive done this wrong, but Ive started with the GE as input and the 5687's as gain and am getting nice and clear sound, no judgements yet as its only been on for 20 minutes.

My SE has 2 inputs and a third set of RCA's which I believe is a preamp but it doesnt output anything to my stereo which has been accepting the GS-1's preamp for 6 months just fine. I have sent an email to Mikhail becuase he would know, but I thought some of you might know what it is.

There is also a toggle on the back of the unit, this seems to be voltage as the tubes glow brighter on one setting and i didnt leave it on the higher one for long in case I dont something bad

However I seemed to recall that newer MPX3 SE's were auto biased?

Anyway out of those tubes, can anyone recommend combinations that work together? I know very little about tubes, I have read a whole lot about different ones and am about to buy a large swag of different tubes, but just a little advice to tide me over would be great! Also if as is probable the switch on the back is voltage bias, are any of the tubes I listed fine for using at the higher voltage? What would you recommend as the first 10-20 tubes I should get to start experimenting?

Thanks for any input, this thing is solid as hell and it sounds very natural at this point, I cant put my finger on it but theres just an extra dimension compared to the GS-1.

 

[augustwest]

You can use the 5687's & and 6sn7's as output tubes. Use them only at the 300 volt setting.

Use the 6bl7 & 6bx7 tubes, if you have any, as output tubes and you can use them at the 400 -425 volt setting.

You can also use the above tubes as input, but the voltage selector won't effect that.

When used as output tubes you should run them as matched pairs, for instance you could use the two Westinghouse tubes as output, with the GE 6sn7 as an input tube. Or you could run the GE 6sn7 as input, with te two 5687's as output. Experiement some to see what you like the sound of.

- augustwest

 

[alex_cs]

ok thanks, so even though the two westinghouse are different, one actually says RT on the top, they are in fact a pair?

 

[panyncor]

Quote:

Originally Posted by alex_cs /img/forum/go_quote.gif My SE has 2 inputs and a third set of RCA's which I believe is a preamp but it doesnt output anything to my stereo which has been accepting the GS-1's preamp for 6 months just fine. I have sent an email to Mikhail becuase he would know, but I thought some of you might know what it is.

Try removing the headphones. On my MPX, the RCA outputs "engage" when the headphones are unplugged. (I asked Mikhail the exact same question when I got mine and couldn't get any output. He pointed out that, that because of this, you don't need to keep headphones plugged in as a load when the amp is on.)

You can try one of the 5687's as an input tube if you want. I don't care for it, but there are some people who do.

I definitely recommend getting some 6bx7's. They're not very expensive ($10-$12 US) and are easily my favorite output tubes. That's true even though I'm not running them at the best possible bias (which is something that your SE allows you adjust).

Enjoy!

 

[alex_cs]

ok thanks for that! worked perfectly

What a nice guy Mikhail is, I didnt even ask for a preamp nor pay for one

I tihnk ill have to get some adaptors like the Ecc1,2,2c51 and get busy.

currently running the westinghouse 6sn7gt as driver, the 5687's as gain (would still love to know what brand they are, almost looks like they say raytheon on the side but its too rubbed off the tell)

Thanks again.

 

[sacd lover]

Quote:

Originally Posted by alex_cs /img/forum/go_quote.gif ok thanks for that! worked perfectly What a nice guy Mikhail is, I didnt even ask for a preamp nor pay for one I tihnk ill have to get some adaptors like the Ecc1,2,2c51 and get busy. currently running the westinghouse 6sn7gt as driver, the 5687's as gain (would still love to know what brand they are, almost looks like they say raytheon on the side but its too rubbed off the tell) Thanks again.

They are Raytheons judging from the PRINT color. The Westinghouse 6sn7gt could be anything.

 

[alex_cs]

do the numbers 337 4r13 mean anything?

 

[alex_cs]

Really enjoying the sound of this amp, I cant say what it is I like about it but it gives you something extra on top of the GS-1.

How long do these things usually like to settle down? And how about tubes? hundred hours, less, more?

Ive thought of the quality of this amp. Weight! It gives a sense of weight and presence I didnt hear before. Also a sense of being more in control of the sound. I seriously cant wait ot try the 6bl7/6bx7. what else is recommended for a beginner, the 7n7, 2c51, anything else?

 

[mateo05]

I recommend putting in a pair of 6BX7 as output first; they're the most transparent output tube I've tried. Then, roll the driver tube as you see fit, and if you want a little bit extra warmth/weight, go to 6BL7GT/A's as output. If you want a more intimate presentation, try the 5687 as outputs. I also like the 5687 as gain, so you might want to try that.

For the high voltage switch, I'm pretty sure that turned to teh right is high voltage (definitely use this for the 6BX/BL7's, thats the reason for this amp in the first place), and the left is for low voltage (5687's).

 

[sacd lover]

Quote:

Originally Posted by alex_cs /img/forum/go_quote.gif Really enjoying the sound of this amp, I cant say what it is I like about it but it gives you something extra on top of the GS-1. How long do these things usually like to settle down? And how about tubes? hundred hours, less, more? Ive thought of the quality of this amp. Weight! It gives a sense of weight and presence I didnt hear before. Also a sense of being more in control of the sound. I seriously cant wait ot try the 6bl7/6bx7. what else is recommended for a beginner, the 7n7, 2c51, anything else?

If you have some good 6sn7gt's for gain .... just get a construction matched = physically identical pair of 6bx7gt's you can try out at high voltage. That will keep you busy for quite awhile.

 

[alex_cs]

thanks for feedback. earl are you suggesting the 6sn7gt's i have are any good, or you cant be sure?

the 5687's seem a lot more punchy than the 6sn7gt's i have, when put in the gain position.

Im on the verge on ordering a few tubes and have shot you an email regarding place of purchase re: what you told me a few months ago.

thanks mateo05, ill definitely be getting the 6bl7gt and 6bx7gta amongst others.

ive realised ill have to get the adaptors first though, i understand theyre the most expensive part

 

[PFKMan23]

Quote:

Originally Posted by alex_cs /img/forum/go_quote.gif thanks for feedback. earl are you suggesting the 6sn7gt's i have are any good, or you cant be sure? the 5687's seem a lot more punchy than the 6sn7gt's i have, when put in the gain position. Im on the verge on ordering a few tubes and have shot you an email regarding place of purchase re: what you told me a few months ago. thanks mateo05, ill definitely be getting the 6bl7gt and 6bx7gta amongst others. ive realised ill have to get the adaptors first though, i understand theyre the most expensive part

I'd definitely get some better 6sn7s or get some adapters to use other tubes, as there are much better tubes to use for gain or output.


And FYI, that's 6BL7GTA and 6BX7GT. You have the designations reversed.