Let me respond to the original posting, and you can still disagree if you want.

Posted by Kurt Strain on July 27, 2002 at 11:03:28

In Reply to: Re: Which PP pentode amps sound like solid state ? posted by john dem on July 26, 2002 at 22:21:03:

>>PP will give you more power, and better bass.

I agree, for tubes at least with zero NFB, without even trying hard. As a result, you get better bass control since the power supply modulations are 100 times less on average than a similarly built SE.

>>SET will give you (IMO) a _much_ more musical sound, but lower power, hence requiring more efficient speakers.<<

That's your opinion, and I agree. For it to show its musical qualities, the prerequisite is a suitable speaker to match. A very natural sound to me. For more detail and bass tightness, trying to hope for PP bass, more PS circuitry and design is required, something that can also be applied to the PP amp and then the PP amp wins again in bass.

>>PP sounds somewhere in between solid state and SET to me.

I agree since I know you mean PP tube here. SS amps are almost all PP designs, except for a few, like Pass designs. Tube PP will diminish the even order distortion and not cover the odd ones well. PP is a topology that does this, no matter the device, so expect some degree of residual PP sonic signature in all PP amps. My PP45 amp is great for bass performance and tone, but is bettered by all my SET amps for tone. Therefore, I find PP tube amps similar to SS amps and SET amps in that they share much of each of those characteristics, and hence lies somewhere in between in terms of sound. Now this PP45 will easily be liked by many as the ultimate compromise, just plain best amp. But if you gotta have all the SET tone you can get, get a SET. If you gotta have all the bass control you can get, get a SS PP amp. The PP triode amp is in between.

>PP triodes are better than PP pentodes however.

That's your opinion, by using the term "better", and I generally agree. The best PP pentodes are still awesome, IMO, and do better than triodes sometimes. I love the KT88 PP AirTight ATM-2, for example, as one of the best high power amps I could get. For low power, I'm inclined to look for small triodes and small high quality transformers to get more of everything.

>>A big PP pentode amp with negative feedback starts to sound so much like SS amps that I wouldn't bother. :-) <<

Some common commercially successful amps are that way, such as Audio Research. They start overlapping into some good MOSFET and bipolar designs. I've heard that the bigger the pentode amp, the more SS sterility they get unless much is worked on, and I have nothing that tells me it would do otherwise. Then the amps get so expensive that a lot of voicing tricks are justified and explored, but big paralleling makes them sound more SS to me. Same is true of massively paralleled triode amps in many cases, like OTLs, IMO. Less is true about the Music Reference RM-9 I had, since it was pretty silky with good EL-34's, but not the tone nor detail of smaller DHT triode PP, and nothing like a SET, even a EL-34 SET using the same tubes, as I once had. More SS sounding for sure, but not extremely so in that case. PP pentodes are a step toward SS sound compared to triode PP, almost always as my experiments tell me. More massively paralleled pentodes get worse, and even in SS, more massively paralleling transistors makes it get generally more bleached out, "SS-like". The better transistor amps for your money will go to the low powered amps, in all likelihood, using no paralleling.

Physics are physics, but evaluation of the physics demands an opinion about that. There are many processes for making IC's for example, because there's usually a best one for the application in mind.

Kurt

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Follow Ups Full Thread

Topic - push-pull triode vs single ended triode - c3conv 23:52:02 07/25/02 (21)

"regardless of speakers" - newbee 09:05:39 07/26/02 (0)

Re: push-pull triode vs single ended triode - Andrewbee 07:39:01 07/26/02 (0)

Re: push-pull triode vs single ended triode - Robert H. 06:26:35 07/26/02 (0)

Re: push-pull triode vs single ended triode - akshobhyavajra 05:03:04 07/26/02 (2)

Re: push-pull triode vs single ended triode - beatones 06:40:43 07/26/02 (1)

Re: push-pull triode vs single ended triode - akshobhyavajra 06:50:57 07/26/02 (0)

Re: push-pull triode vs single ended triode - Oscillatus 01:53:40 07/26/02 (14)

guitar amps - steven oda 11:07:24 07/27/02 (0)

Which PP pentode amps sound like solid state ? - john dem 08:07:18 07/26/02 (12)

Re: Which PP pentode amps sound like solid state ? - Oscillatus 20:27:12 07/26/02 (11)

Why do you think your prejudices are helpful ? - john dem 21:49:19 07/26/02 (2)

Gee, I thought this forum was moderated. - Oscillatus 00:18:56 07/27/02 (1)

Have you ever been fired from a Shinola factory ? - john dem 11:38:15 07/27/02 (0)

Re: Which PP pentode amps sound like solid state ? - Kurt Strain 21:14:18 07/26/02 (7)

Re: Which PP pentode amps sound like solid state ? - john dem 22:21:03 07/26/02 (6)

Let me respond to the original posting, and you can still disagree if you want. - Kurt Strain 11:03:28 07/27/02 (3)

Hmmm.... - Oscillatus 17:19:24 07/27/02 (0)

Some things we might agree on - john dem 14:08:22 07/27/02 (1)

I'm not sure we're disagreeing except on perspective taken. - Kurt Strain 15:23:56 07/27/02 (0)

Well, if PP sounds like SS, I have been screwed for years... - Robert H. 07:07:58 07/27/02 (1)

Sorry, I am not inclined to react to your flaming. <nt> - Oscillatus 07:11:31 07/27/02 (0)

Follow Ups

Let me respond to the original posting, and you can still disagree if you want. - Kurt Strain 11:03:28 07/27/02 (3)

Hmmm.... - Oscillatus 17:19:24 07/27/02 (0)

Some things we might agree on - john dem 14:08:22 07/27/02 (1)

I'm not sure we're disagreeing except on perspective taken. - Kurt Strain 15:23:56 07/27/02 (0)

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