A couple of tube-related observations and questions

jcaut · February 2006

Bear in mind that these come from a relative "tube newbie".. My only piece of tube gear is a Dodd ELP preamp.

I find that the "tube sound" is more obvious (in other words, the tubes sound more different than solid state) at higher volumes. Let me rephrase that, for clarification: ....more obvious at higher volume settings on the pre. Higher gain I guess is what I'm trying to say. Curious if anyone else has observed this. It causes me to crank things up a little more than I might otherwise, because it sounds better. Of course, I don't like to listen crazy-loud all the time. I know several people have remarked that the ELP is pretty "hot". I find that to be true on my system. 1/4 turn of the volume is about the max that I would listen to, under "normal" conditions. "Tricycle" calls for about 1/3, maybe. What is it, besides obviously the volume pot, that controls the gain of the preamp? Is it a characteristic of the type of tube used? I performed a little modification on my old Carver C-1 where I changed a couple of resistors to lower the overall gain of the pre. Carver claimed that it's better to be able to operate the pre at a mid-range volume setting. I think it was more of a "noise floor" issue. I'm getting off track.. I'm thinking I might get better sound if I was able to utilize a higher volume setting. Perhaps with an amp with lower gain, or a source with a lower output level.

I've tried a variety of current production tubes in the Dodd. My favorites are JJ's, I think. The Russian tubes sound almost like SS, to me. Ei's are warm and soft.. lacking detail, again, to my ears. NOS JAN 6922's (I've got some blue label ones dated 1/87 and some green 3/86, but they sound the same to me) are perhaps the best compromise between the tubey highs and strong, tight bass.
RuSsMaN recently fixed me up with a set of Amperex BugleBoys, made in Holland. These sound like what I used to imagine when I would hear people describe the "tube sound". The highs are sweet, but the bass seemed to lose definition. I wouldn't have noticed it so much before I got the SRS 2's, but it seemed rather obvious to me now.

Does anyone know who makes the Groove Tubes 6922's? They sound a lot like the JJ's, to me-- I like 'em. I haven't compared them visually to see if the construction looks the same. Just curious, if anyone knows.

Last question: The other day when I was listening to some music, my electricity "blinked" off for a second. It sent a nasty pop through my system (fortunately I had some DIY speakers connected at the time, though it apparently didn't hurt anything). I'm guessing that the pop had to do with the voltage drop to the tube pre, but I'm not sure. Does anyone connect their gear with some sort of battery backup?

Thanks for any info!
Jason

Early B. · February 2006

jcaut wrote:

I find that the "tube sound" is more obvious (in other words, the tubes sound more different than solid state) at higher volumes. Let me rephrase that, for clarification: ....more obvious at higher volume settings on the pre. Higher gain I guess is what I'm trying to say. Curious if anyone else has observed this.

Yeah, tubes sound much better than SS at higher volume. With tubes, if you increase the volume, the clarity remains, but with SS you quickly get into an annoying, distortion type thing.

candyliquor35m · February 2006

For me just the opposite happened...I find myself listening at much lower volumes between 1/4 - 1/3 whereas I used to crank it to 1/2 (12 o'clock) quite a bit. I hope to switch back to SS for awhile to compare the two.

Stew · February 2006

jcaut wrote:

It causes me to crank things up a little more than I might otherwise, because it sounds better. Of course, I don't like to listen crazy-loud all the time. I know several people have remarked that the ELP is pretty "hot". I find that to be true on my system. 1/4 turn of the volume is about the max that I would listen to, under "normal" conditions. "Tricycle" calls for about 1/3, maybe.

Jason - I don't have any experience with tubes but, for comparison, I had a similar experience with opamps. I recently tried several different opamps in my CD player and found that Burr-Brown (Texas Instrument) opamps are soft and laid-back sounding while AD (Analog Devices) opamps are more punchy and dynamic. IMO, the AD opamps sound a lot better than the B-B opamps at low volume and I don't feel the urge to crank it nearly as loud. They both sound good at higher volumes. FWIW, I'm guessing there's a similar difference between different tubes.

madmax · February 2006

I also find myself listening at lower volume levels with tubes. When I had SS it sounded like crap at the lower levels. Lets face it, whether you listen loud or soft, tubes just sound better.
madmax

BobMcG · February 2006

The last SS pre on my main 2ch rig worked great at low and moderate levels and I thought it worked great at high levels, untill I put the DODD MLP into the system. Now higher levels are clearer than ever, and I do listen at fairly high (loud) levels. That hasn't changed.

reeltrouble1 · February 2006

I have read several places during research that the gain control is more accurate with less noise past the mid-way point. I tried it a few times when I had amps with seperate gain controls on the amp, I dunno, it was kinda cool, but it just kept bothering me seeing the gain knob on the pre jacked around to 3:00 or so. Everything sounded fine, but I was just not comfortable with it.

As far as the tube for the Dodd, there are so many variables its truely a case of which one you fall for. I am digging the Amperex 6DJ8 right now.

The tube output does distort the signal, much more than a comparable ss pre will, its just that most folks, myself included, like the way the distortion sounds as it tends to soften the treble making you able to crank it a bit without the fatigue setting in. The ELP distorts the signal differently than MLP resulting in the MLP sounding a bit smoother, at least to my ear. All of this is set against a tube with its own charachteritiscs. You might want to research tube biasing.

What you have with the Dodd is a well thought out circuit, that is where it all begins and if that is not right nothing is going to really fix it. Add to that the hand point to point wiring, Sonic caps, fast diodes and so on, it all adds up to one mighty little box.

RT1

Tour2ma · February 2006

Missed this little write-up earlier... Nice read.

A couple of tube-related observations and questions

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