Tube rolling recommendations for Eastern Electric MinMax Preamp?

Timothy Smith

I just purchased a used Eastern Electric MinMax tube preamp.

I really like the sound. It has the stock tubes which consist of:

(1) 6x4
(2) 12AU7

Do any Club Polk members have experience with this preamp, and can they recommend some other tube to try?
Thanks,

Tim

brianle

It depends on what are you trying to improve over the stock tubes ...

Timothy Smith

brianle wrote: »

It depends on what are you trying to improve over the stock tubes ...

Thanks, but I am not trying to improve or correct any flaws.

I just started listening.

I usually like what I hear until I hear something better (or worse), just looking for some suggestions to try.

I have gone through a progression of different tubes types and brands in several different preamps, power amps, an integrated amp, and a tube buffer. That's part of the fun. I wish it was that easy and inexpensive to experiment with the sound qualities of solid state equipement.

erniejade

What brand of tubes are in it now?

zingo

erniejade wrote: »

What brand of tubes are in it now?

I'm going to guess Chinese. Most of us can make recommendations for tubes, but we also need a price range.

ratster

Did you decide to do this instead of a new CDP or DAC?

heiney9

Sylvania JHS-5814 3 mica Black plates or GB (gold brand) 3 mica. Many claim they are the same sounding tube

RCA 12AU7 clear tops get a lot of recommendations, but they aren't my favorite

Sylvania JHS 12AU7

Amperex (Holland made) ECC82 short plate w/ large halo getter. Excellent balance, lots of air and focused but still a glorious midrange

Mullard (Mitchum made) ECC82 usually 1959 or 1960. They are hard to find compared to Blackburn made tubes, but they are fantastic. Mitchum tube seems to have more focus and less syrupy sound. Same air and soundstage and great midrange bloom. A tad less bloated than the Blackburn produced tube.

Many feel these are too die for Amperex (Holland made) 7316 long plates. Scarce and extremely expensive.

Raytheon 5814 3 mica black plate w/windmill getter. Also rare and expensive. A nice alternative would be the 3 mica black plate version with the square getter.

My favorite but even more scarce than the 7316 long plates are the 1955-57 Valvo Hamburg long plate ECC82 D getter with foil bar the getter is attached the wing tip sticking up through the mica.

Just something to chew on

doctor r

I have no direct experience with your unit, but the RCA 12au7 cleartops are ones i think would be interesting to try. They can be a little bright on top, but that works in some applications well. I have found some tung sol 12au7s that are very linear in their presentation with a nice high end openness and shimmer, but without the cleartops's brightness. Tried the Psvanes and was not too impressed. Amperex white label or bugle boys are really nice in the right setup, but the orange labels leave me a little disappointed. Have fun.

heiney9

Orange label Amperex are a far cry from the early Amperex. At some point the Orange label one's were manufactured by Richardson Electronics and they don't have any of the "classic" Amperex traits, or atleast they aren't as apparent.

Speaking only from my own experience, I like tubes manufactured before about 1968, with the late 50's and early 60's being the best sounding to my ears in my various tube pieces of gear. I know that's a broad generalization, but I have tried a lot different types of tubes and it seems that idea runs parallel amongst them all for me.

H9

doctor r

Totally agree with H9.

Timothy Smith

erniejade wrote: »

What brand of tubes are in it now?

I think it still has the original Chinese tubes.

I swapped in a Genelex Gold Lion 12AU7 in the center position and rolled on some silicone O-ring dampers and it already sounds better. Bass is much deeper and solid. Sounds more sweet overall.

This is fun. I have a few more to try, but nothing old or exotic.

Thanks.

heiney9

Tim if you are interested I might have a spare pair of older Sylvania's. Let me know and we can discuss.

H9

george daniel

GEC rectiifier and Siemens nickle plates(2)

heiney9

Hey ya George!

Those chrome plate Siemens have become sort of scarce and the price seems to have gone way up. Another tube that I just won't spend that much on unless I'm sure I like them. How would you characterize the sound?

H9

heiney9

Have you read up on the unit? You realize each tube handles the left and right channel of two different stages. Input buffer and Output, so you don't have to use matched pairs of tubes and can mix and match single tubes since they are each in a different part of the circuit.

Read here if you haven't already

http://www.enjoythemusic.com/magazine/equipment/0503/easternelectric.htm

Especially this article

http://www.tnt-audio.com/ampli/minimax_pre_e.html

I am even thinking about perhaps picking one up and putting against the Dared and keeping the one I like best. Except no remote

H9

Timothy Smith

heiney9 wrote: »

Have you read up on the unit? You realize each tube handles the left and right channel of two different stages. Input buffer and Output, so you don't have to use matched pairs of tubes and can mix and match single tubes since they are each in a different part of the circuit.

Read here if you haven't already

http://www.enjoythemusic.com/magazine/equipment/0503/easternelectric.htm

Especially this article

http://www.tnt-audio.com/ampli/minimax_pre_e.html

I am even thinking about perhaps picking one up and putting against the Dared and keeping the one I like best. Except no remote

H9

Thanks!
If your van down by the river is near me you can borrow my EE to try in your system before you go buying one.

george daniel

heiney9 wrote: »

Hey ya George!

Those chrome plate Siemens have become sort of scarce and the price seems to have gone way up. Another tube that I just won't spend that much on unless I'm sure I like them. How would you characterize the sound?

H9

Well balanced-- detailed,, not bright,,, my minimax responded well to tube rolling,,I'll look up the tube recipe that I had in mine,, the one I had was modded by Tutay,, the gain was lowered among other things,,sweet little pre-- different from the dared in so many ways,I'd still have mine if it had a remote!

heiney9

I found a source for NOS 50's Tung Sol Black Glass, Black Plate, D-getter 12AU7. The big thing for me is lack of remote. If one came along at the right price I'd probably pop for it. I have enough 12AU's and variants to keep it interesting for quite awhile.

H9

Dawgfish

A couple other recommendations for 12AU7s would be the CBS Hytron Blackplate 5814 and RCA Triple Mica Blackplate 5814s. If you are looking for more bass the RCA is your tube. The CBS is better balanced.

The best 6X4s I've tried are the Brimar Blackplate 6X4, Tung Sol 6X4, and Phillips Holland 6X4 (Eindhoven plant, they are very rare, most you see on the market are from Argentina).

george daniel

IIRC I had a Tungsram ECC 80something in the middle tube position a Siemens "silverplate" in the far right and a GEC 6x4 rectifier-- I still have a few 6x4's,, let me know if you want any-- FWIW I thought the Dared has/had a better bottom end the the minimax,, while the mini does a tad better on the highs,, or maybe it's just the tubes,, or maybe I was high. Have fun!

Timothy Smith

Thanks but.....

ALL212

My favorites are the old Tesla ECC802S (I don't remember which color label are older, yellow or white) - around $100/pair, E80CC's (a little bit less gain and taller than standard 12au's but in an open pre you have no worries about fitting them in) - less than $100/pair. 7316's aren't that far above these in price and are not rare at all - just not as plentiful as stock 12au7's or Ecc82's. A trio just sold for under $150 on the bay recently if you can get a pair for that price you've done well. If you have piles of cash laying around buy a quad of Telefunken Ecc802S's and give me two of them! :eek:

Other good tubes are the RCA 5963 black plates and Siemens 5814's.

Please don't confuse rare or expensive with good sound. A person I know who builds tube pre's all the time prefers 5814's over everything but they don't trip my trigger. One advantage of gold pins is that when you get them you won't have to clean them!

If you intend to try and resell - probably not a great idea. Most folks won't buy bay tubes unless they've been recently tested and you should follow that lead. If you're not intending to try and resell them then it won't matter. Balanced triodes are important as badly balanced tubes may be a sign they are failing and tubes that test badly or haven't been tested (NOS may be an exception) should be avoided.

I would buy pairs to try in that pre until you find something you like. Then start replacing one to see what the sound is like. Combinations of even just two tubes can be overwhelming!

heiney9

Amprex Holland 7316 long plates are very rare and expensive.

ALL212

heiney9 wrote: »

Amprex Holland 7316 long plates are very rare and expensive.

But "normal" 7316's are not and in my post I did not specify "long plates" so why repost what you originally stated? Did you feel that I was contradicting you?

So - just to be clear. 7316's that are NOT long plated are not only NOT rare but also NOT prohibitively expensive. If you'd like to know more on the long plated version please PM Brock.

SMH...

heiney9

ALL212 wrote: »

But "normal" 7316's are not and in my post I did not specify "long plates" so why repost what you originally stated? Did you feel that I was contradicting you?

So - just to be clear. 7316's that are NOT long plated are not only NOT rare but also NOT prohibitively expensive. If you'd like to know more on the long plated version please PM Brock.

SMH...

Wow, touchy. Didn't mean it that way at all. Just reiterating that when I said they were pricey and rare (IMO) I was referring to the long plate version. Nothing more nothing less.

I guess we all define "rare" differently too.

Sheesh this place is a chore sometimes.

heiney9

FTR,

I didn't realize I was specific about long plates in my earlier post until I went back an read it AFTER I posted about them again. So my bad for repeating myself.