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EAR HP4 Tube Rolling Thread - Page 4

post #46 of 78

ALESA VAIC 300B

Ohh... my friend, if you what a very hi improovment in your Manley change first the Sovtek 300B with the Alesa Vaic Reference, not so expensive as the WE, but even better performance. I also bought the ECC35 Mullard 1957... for the 6SL7

Best!
Nicola
post #47 of 78

Alesa vaic

They are really better ? I've read some good review about them; but also i'm curious about the WE, you know the "legend" and all that stuff...

I didn't make any decision yet...i think i will try to buy both so i will compare and maybe post a review.
post #48 of 78
Thread Starter 
Just tried some Tung Sol VT-229's in the HP4. Weird tube. On initial listening, it had a lot of promise. However, as the tubes burned in, the highs went away, and the bass got bloated. They never recovered. So, I'd say avoid this one. I tested with HP-1, and simply cannot find any redeeming features to that tube.
post #49 of 78
Quote:
Originally posted by Hirsch
Sylvania VT-229 dated 1944. Tall bottle, black plates. The most detailed 6SL7 I've heard. Immense increase in depth of image. Slightly dark sound, minimizes transformer coloration. Very smooth. This tube is a superb driver for the HP-1. There may be a slight loss in dynamics compared to the GE or Valvo tubes, but it's not a problem with HP-1 (although it's a bigger problem with R10). This could be my favorite tube for the HP4 so far.
Hi Hirsch,

i'm convincing my self of the same thing... I'm now listening my EAR-HP4 / Grado PS-1 with Sylvania VT-229 1944: very, very good!

Are you still in this idea about these tubes? The tubes are taller than other brand, but they fit right, right in the EAR (!!!).

Best!
Nicola

Thanks to Hirsch for his great help in tuberolling experiences!

PS:

This is what Tim de Paravicini wrote to me:

"Yes you can try other 6SL7 tubes from RCA etc., The ECC35 was a close equivalent but has 400 MA heater not 300 MA as the 6SL7 has. To me the design of the circuit is more important than the tube maker".

So I do not use more the ECC35 ...
post #50 of 78
Thread Starter 

ALERT: older tubes wearing too fast

In preparing my HP4 for shipment to its new home, I tested several sets of tubes that are going with it. To my surprise, I found that some of the tubes showed signs of major wear, even though they did not have a lot of hours on them. These turned out to be older tubes used as the output tubes (closest to the transformers). Tubes that showed significant wear included the Sylvania VT-229, Raytheon VT-229, and Valvo 6SL7GT. Some of these tubes were brand spanking new. After only a few weeks of use, they test as though they had thousands of hours on them.

There was no significant wear in the other pair of the quad, used as the drivers. The one thing that these have in common is that they are older tubes. I suspect that construction of the 6SL7GT changed somewhere around the late '50s. The stock Sovteks show no sign of wear in the output position, nor do the Amperex (GE) 6SL7GT, or any of the 6SL7WGT's that I tested. My guess is that the older tubes would last 6 months to a year in regular use (maybe less), based on the change in Gm I saw.

Recommendation: If you're going to use vintage 6SL7GT's, use them as the driver tube. That has the most influence on the sound, IMO. For outputs, use the stock Sovteks, a pair of 6SL7WGT's, an Amperex or other tube vintage 60's or later. That's all I've checked so far. An alternative strategy would be to buy a LOT of your favorite older 6SL7GT. If my measurements are correct, you'll need them. If anyone else has checked vintage tubes for wear after they've been in the HP4, please post.
post #51 of 78
Hirsch,

considering even this aspect (life of the tubes) wich brand you' d keep for the EAR/Grado combo? Amperex GE ? Or what?

Thanks a lot!
Nicola
post #52 of 78
Thread Starter 
Quote:
Originally posted by Nik
Hirsch,

considering even this aspect (life of the tubes) wich brand you' d keep for the EAR/Grado combo? Amperex GE ? Or what?

Thanks a lot!
Nicola
Nik,

I just found this out when I packed the amp, so I haven't tried different pairs. Amperex and GE are the same tube (if there's a wire between the two filaments), and it's a very good tube. If I was keeping the EAR, my next move would likely be Raytheon VT-229's as drivers, with Amperex as outputs. If I'm right, that should give you most of the benefits of the Raytheon without wearing tubes out too fast. If it adds some of the punch of the Amperex to the midrange of the Raytheon, it could even turn out to sound better than a quad of the same tube.

If you like the Sylvania VT-229's, they should be safe as the first tube in each channel (toward the rear of the amp). The output tubes (close to the transformers in front) are the ones that showed wear.
post #53 of 78
Hi Hirsch,

what the different in sound between the Raytheon and the Sylvania vt-229?

Please tell me thinking to the EAR/Grado nor thinking to the R10.

Do you prefer the Raytheon than the Sylvania even with your HP1000?

Thanks a lot!
Nicola
post #54 of 78
Thread Starter 
Quote:
Originally posted by Nik
Hi Hirsch,

what the different in sound between the Raytheon and the Sylvania vt-229?

Hi Nik,

I had the Sylvania's and the Raytheon's in the HP4 in different systems, with different cabling and different sources. There's no real way to compare them. FWIW, I really loved the Sylvania VT-229 with the HP-1. It got a clarity out of the HP-1 that I hadn't heard before.
post #55 of 78
Hi Hirsch,

do you remember if the Raytheon fit in the HP-4?

Thanks a lot!
Nicola
post #56 of 78
Anyone got any ideas as to why the NOS tubes nearest the transformers are wearing out this fast?
post #57 of 78
"They should last between 1500-2000 hrs. as long as you don't turn on and off the amps frequently or leave them on all the time".

This what I received as answer from Kenneth Chait ...

No so much 1500-2000 hrs !!!




Best!
Nicola
post #58 of 78
Who is Kenneth Chait?
post #59 of 78
post #60 of 78
Thread Starter 
Quote:
Originally posted by Nik
Hi Hirsch,

do you remember if the Raytheon fit in the HP-4?

Thanks a lot!
Nicola
Yes,

The Raytheons I've seen are short-bottle tubes that fit in the original case easily. That's one of the reasons I like them
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