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Hi All,

I'm new to tubes, but I just bought a pretty nice Pacific Creek E34I integrated valve amplifier.

It is an ultra linear design with four 6sn7 tubes in the preamp/predriver section, and four EL34B tubes in the output section.

The guy that sold it to me said he carefully chose to upgrade the Shuguang preamp/predriver tubes with some Sylvanias, and he didn't think I should waste any time fooling around with them.

He did suggest that I should experiment with the Shuguang EL34b output tubes however.

The amp sounds pretty awesome, but does anybody have any recommendations or advice on how to learn about the qualities of all the different models of tubes?

My only criticism of the amp at this point, is that I lost a little bit of low bass growl coming out of my speakers when I switched from solid state, and my classical music lost a little bit of it's projection into my room.(I want to call it a lack of brilliance, but the high detail is still there. It just doesn't sound like i'm in the hall anymore. It's kind of like i'm listening to the orchestra from one of the doorways into the hall.)

Thanks,

Chris

Nice looking amp! At a very nice made in the good ole USA price!!!

Lots of experience in the club with PP guys using EL34s. If I remember correctly, the "best" are probably Shugang Treasure tubes. Reproduction Gold Lion I know are excellent as well. NOS Mullard are right there with the best (some say certain versions ARE STILL the best).

As for input tubes and "new" production, I believe that there is a Soviet military tube, 1578, purported to be fantastic. I have some 6SL7 equivalents, 1579, and they are as advertised.

http://www.ebay.com/gds/Find-best-repla ... 806/g.html

That amp seems to have great modification potential. Be prepared to familiarize yourself with Parts Connexion! Duelund Cast PIO caps. Handmade sells wonderful IRC resistors. Mills resistors, Cardas wire. don't forget your Walker Valid Points! You'll be listening to power cords and interconnects, speaker wires and other tweaks!

Nice, nice find!

As to the lack of projection or brilliance, tweaking the combination is everything.

Did they provide, or can you reverse engineer the circuit? Is it the classic Williamson?

https://en.wikipedia.org/wiki/Williamson_amplifier

Thanks Stuart,

The guy that sold it to me taught me a lot of stuff in a really short period of time before he pitched the amp to me. I didn't even know what Bias was before I met him.

Yes, I have a circuit. I might be able to scan it an post it. I know how to identify all the components, but the topology doesn't mean very much to me yet.

I might try to experiment with some Mullards. They are not that expensive, and you can get them on ebay.

All that other stuff maybe at a future time, but it is nice that it is point to point wired so it's pretty easy to snip out, and solder in a new component. So what is the first thing I would do, replace NPE's with poly caps maybe? What is a PIO cap?

Chris

Although the lure is strong, I'd hold off on swapping parts for the moment. The stuff that is in there is probably at least OK, if not the greatest "name brand" audio jizz componentry known to Man.

First thing to do is make sure all of those bias supplies are set properly. That design offers great opportunities to get totally out of whack with all of the adjustments.

I have never used Chinese tubes but the second thing I'd do is make sure you have a good pr of power tubes. The stock Chinese might be decent, if still good, but I can't pass judgement. Many manufactures will ship with the cheapest junk tubes, figuring that the ultimate tube choice is the job of the owner (while passing along the costs at the same time). You won't have to look far to find folks who have surveyed the options and can offer impressions.

Finally, listen to it for a while and learn the personality of the amp. If you are unfamiliar with the flavors of tube amps, the necessary modification might be to your ear and sonic expectations, learning what the amp does. There are totally different modes of presentation from what you are used to and it might be too soon to judge. The lack of forward HF information that you describe seems to me a good thing about tube amps of that genre. You mentioned that the highs are there but not in your face. Yeah, that sounds about right.

Need I add that the voicing of the speakers enters into play? Some "high end" speakers are flabby as cow snot on tube amps (like that metaphor? ) and you will find that tube guys generally go for a vivid, immediate sounding speaker. I say "generally" but there are no universally valid generalizations.

All in all, my point is to figure out where you are before you go heading off into the vast abyss of tweaks and mods. When you get to that point, I am sure the crazed nerds on this and other forums will have many intriguing suggestions.

All in all, my point is to figure out where you are before you go heading off into the vast abyss of tweaks and mods. When you get to that point, I am sure the crazed nerds on this and other forums will have many intriguing suggestions.[/quote]

Yes, I am still getting adjusted to the amp. I have had it for a little over a month, but there are still lots of recordings in my collection I haven't heard yet. I'm also still fooling around with a couple different CD players at the same time, so I think I need to get things stable for a while before I proceed.

Does anything bring back some of the low bass growl that I lost when I switched from solid state, or is that just the flavor of tubes that the bass is more subtle?

Thanks,

Chris

Try using the 4 ohm taps. That will (effectively) lower the output impedance of the amp, and provide higher damping factor, plus more current. It may produce less power, if your speakers are actually 8 ohm......

chris1973 wrote:Does anything bring back some of the low bass growl that I lost when I switched from solid state, or is that just the flavor of tubes that the bass is more subtle?

FerdinandII wrote:Try using the 4 ohm taps. That will (effectively) lower the output impedance of the amp, and provide higher damping factor, plus more current. It may produce less power, if your speakers are actually 8 ohm......

chris1973 wrote:Does anything bring back some of the low bass growl that I lost when I switched from solid state, or is that just the flavor of tubes that the bass is more subtle?

Yes, the speakers are 8 ohm. Using the 4 ohm taps wont hurt the amp? it's not like using the 8ohm tap to drive a 4 ohm speaker, right?

chris1973 wrote:

FerdinandII wrote:Try using the 4 ohm taps. That will (effectively) lower the output impedance of the amp, and provide higher damping factor, plus more current. It may produce less power, if your speakers are actually 8 ohm......

chris1973 wrote:Does anything bring back some of the low bass growl that I lost when I switched from solid state, or is that just the flavor of tubes that the bass is more subtle?

Yes, the speakers are 8 ohm. Using the 4 ohm taps wont hurt the amp? it's not like using the 8ohm tap to drive a 4 ohm speaker, right?

Also, I guess, a loss of power isn't a big deal because my speakers only draw a single watt in most cases, and the amp is supposedly rated at 35 watts.

Almost all speaker impedance curves are, well, curvy...! Except in the places where they have sharp corners. LOL
The idea that any speaker has a single, fixed impedance is generally untrue.



There is NO problem trying the different 4/8/16 ohm taps when driving a typical loudspeaker.

Don't leave them disconnected though.... Some amps will overload the transformers if there isn't some kind of load on the secondary.

Please let us know how it goes, when you try this out.....you should hear a tighter presentation.

FerdinandII wrote:Try using the 4 ohm taps. That will (effectively) lower the output impedance of the amp, and provide higher damping factor, plus more current. It may produce less power, if your speakers are actually 8 ohm......

chris1973 wrote:Does anything bring back some of the low bass growl that I lost when I switched from solid state, or is that just the flavor of tubes that the bass is more subtle?

Yes, the speakers are 8 ohm. Using the 4 ohm taps wont hurt the amp? it's not like using the 8ohm tap to drive a 4 ohm speaker, right?[/quote]

Also, I guess, a loss of power isn't a big deal because my speakers only draw a single watt in most cases, and the amp is supposedly rated at 35 watts.[/quote]