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Update on the tube swap....


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The Tesla KT 88's arrived yesterday and I played them for 2 hours yesterday (replacng the Sovtek 6550WE tubes that came with the amps).

Mobilehomeless had told me that the Sovtek's were not musical and, in a word, he was 100% right!

I didnt know - these were the first tubes I have ever owned. I do now.

The change is remarkable and not at all what I was expecting. Whilst the sound is softer the difference is only slight to my ears. The real changes are 2:

1. Detail. The most obvious - beat you over the head difference. It is a cliche to say a veil has been lifted from the sound but that is exactly how I would describe it. In comparison the Sovtek's were muddy and lose. Previous hidden errors in play are now painfully visible in classical works (I have Grieg on SACD and the orchestra really fluffs the start - I never knew.)

2. Speed. I had thought it was a tube drawback that you couldnt play fast guitar and bass on tubes. True for the Sovteks - not true for the Tesla's. Suddenly I am beginning to doubt whether the Accuphase will be used for the front channels again. It may be softer and smoother, the highs may be more rounded on the tubes but somehow this has come with that amazing change in detail.

The only time I have come across this combination of softness and detail combined together previously was with ESL's (Finals for example).

I am not saying that the Klipsch sound is now like the Final sound, but it is a whole lot closer than I owuld ever have thought possible.

Now the only question is this. There is a quad set of unused, original GE KT 88's for sale on ebay in the UK (with the original boxes and packaging) - these will be a lot more expensive that the Tesla's (they are already at twice the price I got mine for and there are 6 days left).

Do I or dont I?


2 * Heresy 2 (mains)

2 * Homemade horn speakers (rears)

1 * REL Strata 3 sub

Accuphase E211 amp.

Tube monoblocks with separate pre-amp (solid state).

Marantz CD6000 player

Sony NS900 SACD/DVD player

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Humax 5400 digital satellite receiver

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thanks for the tube report, since horns are so much more revealing than cones, it is hard to judge what other people think about equipment (especially when they start to talk about "details and dynamics", please give me a break, or another dictionary for them to use!) -

sorry I can't answer your tube question, though ...


Colin's Music System Cornwall 1s & Klipsch subs; lights out & tubes glowing!

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Love to hear stuff like this. Listen, I try not to steer anyone wrong in this place. Lord knows, I feel as if half the time I am trying to prove myself here as every turn of the corner there is someone expressing doubt concerning this or that aspect. But doubt is a good thing. And so is a questioning nature, as long as it doesnt turn one off to change or new ideas/information. Almost all within this place comes from opinion from experience, either real or imagined. The difficulty comes from weeding out the imagined and trying to deduce the relevance of the REAL. Obviously, experience helps. And an active imagination can be an amusing addition.

Maxg, your results dont surprise me one bit. I knew you would hear this especially given your associated equipment. And the tubes have not even fully broken-in; you will notice a greater sense of ease and a smoothing of the top end as the first 50-100 hours progress.

Welcome to the land of tube rolling, where one can suddenly have a whole new amplifier with the insertion of a few glass valves! Of course, errors and mistakes will take place, and when purchasing NOS, there is the chance of getting burned. But with careful selection, you will be rewarded here.

As for the GE KT-88 auction, I would really make sure you trust this seller before entering into the high priced NOS auctions. It is VERY easy to get burned here as certain tubes have value that all are aware of. If you trust them, that is a start. If the price starts approaching what you can get the tubes from a reputable dealer, then I would personally go with the dealer even if it is a few dollars more.

Wait till you begin changing the input/driver tubes! This will also change the sound with some affected more than others.

Fire me the link for your sale and Ill take a look.


Phono Linn LP-12 Vahalla / Linn Basic Plus / Sumiko Blue Point

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Preamp Cary Audio SLP-70 w/Phono Modified

Amplifier Welborne Labs 2A3 Moondog Monoblocks

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Speaker 1977 Klipsch Cornwall I w/Alnico & Type B Crossover

system one online / alternate components / Asylum Listing f>s>

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So...this is around $325 or so USD, right? So this comes to around $81 or so per tube. Still very good if the tubes are exactly as stated. Of course, this is the mystery...and there are still many days left.

Based on my perusing, these beast could easily double, if not triple, in price if the claimed is indeed, true.

Write the owner and make certain of variables before even considering. You have some time here so take advantage of it. Rest assured, these tube are going to go MUCH higher if people trust this seller.


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Mobile, enjoyed your comments on this thread.

I recently purchased a new AES AE-25 which came stock with:

4 - KT88's ("Electron Tube", China)

2 - 6FQ7's ("EI, China")

2 - 6922's (Sovtek).

I was thinking about upgrading these (I haven't listened to them yet since my Khorns are down in the basement being refinished).

I also got the AE-3 preamp which came with:

2 - 6SN7GT ("Electron Tube", China)

I have a pair of Mullard ECC88 which I think can replace the 6922's ... and a pair of old RCA 6SN7's (1950's vintage). Any thoughts on these?

I read on the net somewhere that the TT21's and TT22's were even better than the GEC KT-88's ... just a higher voltage rating on the grids ... a quad just went (NOS Marconi's) on Ebay (from the UK) for about $175 ... I was curious if you had any thoughts on those, as well.

Bottom line, I guess, since I'm kind of new to this, is that I'll run the Chinese tubes for 100 hours or so as everything breaks in, then maybe start rolling the tubes. Could you make some suggestions (brands, etc.) that might be an improvement without remortgaging the house?



If you don't like what is coming out, you wouldn't like what is going in." -PWK-


Klipsch 1968 ALK Cornwall "II"s (LF/RF)

ALK Belle Klipsch (Center)

Klipsch Heresy (RR/LR)

Klipsch KSW-12 sub

Sonic Frontiers Anthem AMP1 (driving Cornwalls)

Sonic Frontiers Anthem AMP1 (driving Heresy's)

Denon AVR-4800

Toshiba SD-3109 DVD

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Thanks for the additional input mobile. I am watching the tubes - lets see how high they go - if I take part it will only be at the end - but I am not going to go over £100 per tube so I dont fancy my chances.

Right now I am listening to Marvin Gaye on SACD on the tubes - they may or may not be getting warmer - I cant tell - but it sure sounds good to me.

THanks again.

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Thanks for the additional input mobile. I am watching the tubes - lets see how high they go - if I take part it will only be at the end - but I am not going to go over £100 per tube so I dont fancy my chances.

Right now I am listening to Marvin Gaye on SACD on the tubes - they may or may not be getting warmer - I cant tell - but it sure sounds good to me.

THanks again.

Oh yes - and ignore the hecklers. There are nay-sayers on ever forum and I am often in your postion defending high end cables, tubes amps, differences in SS amps, CDE players etc etc.

If they dont hear it (or dont want to) that is fine with me - I only get irate when they tell me what I hear!!

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maxg, glad things are going well... I am serious about the input/driver tubes. I cant remember what yours are, or if you ever even told me, but these can REALLY change the sound and be a missing link to getting that last bit of magic, the kind of magic that happens on those late,late night listening sessions, when the power grid is untaxed and quiet reigns.

Chris, you are in the same boat but have some good options to try. The Mullard will definitely be an improvement in the ECC88 category, although some like the Bugle Boy approach.

As for the 6SN7...man....there are so many options. And the Chinese 6SN7 are lame! They are palatable but the difference in rolling in good 6SN7 will be EASILY noticable; almost all my tube gear has at least two 6SN7s (except the EICOs and the EL-34 amps). And this tube has some great options. The Sovtek 6SN7 STINKS hell and high water and I have not been a lover of any of the Chinese versions as well. I did a monster post on chosing them awhile back and dont remember where it is...

I need to write up that 6SN7 page I did with all the pics ( ) as I have tons of notes on that mess. I will tell you right now that your new amps will sound NEW and better all over again after putting in some good valves. Keep the ones you have as backup. I guess it is wise to break them in..but I can tell you the diff will be rather astounding.

You know, after looking at the GEC KT-88 auction, I can only wonder what the solid state sector is thinking. Why would anyone want to have to pay for "parts" that almost equal the purchase of a whole, relatively decent SS amp? These tube froots are having to repurchase their amplifiers again and again! I can only say that once you go there and "hear," inserting even a TOP notch solid state amp seems to be missing all that is good. At times, I would LIKE to want a solid state amp! I am even hoping to audition a Class A product soon. But even my $100 14w push pull EICO just smoked my excellent B&K 200w Monoblocks as well as the Bryston 4B-ST, two very respectable SS offerings.


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The SM-70's are out of my system and the "doggy's" are back in. I can ship this week...

When I did the amp swap this time I also put in a pair of DIY Superlatives, quite an improvement over the copper/silver interconnect I had been using. I also did another comparison of the KR 2A3's compared to the RCAs, there really is quite a difference!


Ed W

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No I have not told you what my input/driver tubes are.

This is because I dont think there are any. The pre-amp is solid state (made by the same guy that produced the amps). It is connected via RCA to the 2 amps which only have 2 tubes on them - that I have found!

These are my amps: (am I an idiot and missing your question or do they not have input tubes?)


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  • 2 weeks later...

Be very careful buying these tubes as you can get ripped off. I have a great source for some of these tubes - he actually will send them to me first with no money down to hear. If I like, I keep and buy. Cant get much better than that. The vintage RCA you see in that picture is my RCA you see on my Moondog Page. It is a '44 RCA 2A3 JAN CRC VT95 Black Plate. Just be careful as these tubes are more often than not, used.

Is your source credible? Also, are you only getting one? BTW, there is a single GZ-37 on ebay right now.


This message has been edited by mobile homeless on 02-13-2002 at 11:33 AM

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I've been lurking on that GZ37 since it was posted, waiting for the action and bidding to start. Maybe people are leary of the Hong Kong address?

The 2A3 RCA in question is from the same person I got my present RCA's from, so he is credible and has been good for 2 other RCA's, a 1944 and a 1946, both also in their original RCA boxes. I verified all of the above dates with the owner of Tube World as well as the 1943 pair I am currently using. May I ask what you generally pay, which you can email to me if you'd prefer.

I've also located a guy selling tubes who lives in here in the SF/East Bay area. He may also be a possible source for the GZ37. I plan to call him today.

Klipsch out.

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