Pass Labs Aleph 3 & hard to drive speakers

[nightflier]

I was wondering if anyone had used the Pass Labs Aleph 3 amp from a few years ago with hard to drive speakers. I've seen this amp for sale used for about $800 and it seems like a good value, especially considering the reviews, but I will be using it to drive 87dB 4 ohm speakers and was wondering if the amp would have trouble with them.

Also, I presume that the amp will run quite hot considering it is class A, but is this a big concern? i.e. does it run too hot to place on an equipment rack?

[Bernd]

Hi,
Firstly I have no experience with the Pass lab. However 87db/4ohm are not that hard to drive.
This amp should do fine. depending of course on your likes and dislikes and what level you want to play. I did find that class A amps sound much more powerful then the specs suggest. I have driven 86db/3.4 ohm speakers with an 40 watts all tube integrated to high levels.
Just make sure you don't box the amp in. If the warm air can escape you will be fine.
What speakers do you plan on using?
Good luck with the amp if you decide to get it.


The power of music gives you wings

Peace

Bernd

[Geoffcin]

Just make sure you don't box the amp in. If the warm air can escape you will be fine.
Bernd

I've driven amps into thermal overload and it's not a good thing. All Pass gear that I've seen have been either tilted toward class A, or are pure class A up to a certain point. This means heat, and a lot of it. If you amp is in a cabinet then, depending on how loud you like your music and/or you speakers require a lot of current, you can easily overheat your amp.

[Geoffcin]

All the Pass gear that I've heard I've liked. I almost bit on a Pass Labs X250.5 a while back. I heard it driving a pair of Gallo Referance 3's and it was truely wonderful.

If it was made by Pass you can bet it's good.

[nightflier]

Good luck with the amp if you decide to get it.

I'll be driving a pair of MB Quart QLS-830's. I also have other speakers, but the Quarts are my current favorites. The amp is supposed to be stable down to 2 ohms, and I know that the Quarts will dip down pretty far at times.

The Aleph 3 is only 12" square so that will help increase the space around it in the cabinet. The cabinet is large, about 24" deep and 20" wide and the shelves are adjustable. It has an open front (no door).

What also concerns me about the amp iss that several reviewers had stated that it requires a high-output preamp. I haven't heard that about preamps before and I don't quite understand the technical description about why this is so, but I have three different preamps I can try. What spec on the preamps' documentation should I be looking at?

[dean_martin]

What also concerns me about the amp iss that several reviewers had stated that it requires a high-output preamp. I haven't heard that about preamps before and I don't quite understand the technical description about why this is so, but I have three different preamps I can try. What spec on the preamps' documentation should I be looking at?

I looked at this issue a while back. I was looking for a tube preamp/ss amp combination and did some research on the Pass Labs Aleph 30. The main difference between the 3 and the 30 is that the later model (30) was designed to be more compatable with tube preamps. I think if you're going to match the 3 with an active ss preamp you should be fine.

Here's something I posted a while back on specs to look for when matching amps and preamps. I never got any farther on this issue and still don't completely understand it.

"OK, I went back and tried to figure out what's important in matching amps and preamps and though I don't completely understand what to look for I think I found some clues. I had read some reviews of the Pass Labs Aleph 3 amp and its successor the Aleph 30. Due to the Aleph 3's "low voltage gain", it was not a good match for passive preamps (a preamp without active output). The Aleph 30's design included an increase in the voltage gain so it could be matched with not only passive preamps/controllers, but also with some low output TUBE preamps. I also discovered that some tube preamps like the Audio Research SP16L have low output levels presumably to lower the noise floor or to lessen audible "tube rush".

So, I think if you were going to match a tube preamp with a solid state (including single-ended like the Pass Labs) amp, you would need to check the amp's voltage gain and the preamp's output level. The remaining question is what are the threshhold values in amplifier voltage gain and preamplifier output level for a satisfactory match?

I'm not sure but I think I've found some clues. In the review for Audio Research's VS110 power amp and SP16L preamp (which you can find at stereophile.com in the archives), the reviewer tried the two components together and then substituted each one seperately into his system. The SP16L's output level (which the reviewer categorized as "gain") is 11.5dB. The "gain" rating for his reference preamp was 26dB. That appears to be quite a difference. When he put the SP16L in his system, he had some of the same volume problems that Pete noticed. No juice.

On the other hand, the VS110 amp from ARC had a gain of 28dB which the reviewer said was slightly higher than average, but he didn't say what average is. Therefore, the SP16L performed much better with the VS110. The preamp's lower gain was apparently for the purpose of lowering the noise floor, and its lack of juice was compensated for by the slightly higher than average gain from the VS110. So, I think you can conclude that if you were going to get the SP16L preamp for your existing amp, you should check your amp's voltage gain and make sure it's at least 28dB (or, slightly higher than average, whatever average is - maybe 26dB?)"

[Bernd]

I looked at this issue a while back. I was looking for a tube preamp/ss amp combination and did some research on the Pass Labs Aleph 30. The main difference between the 3 and the 30 is that the later model (30) was designed to be more compatable with tube preamps. I think if you're going to match the 3 with an active ss preamp you should be fine.

Here's something I posted a while back on specs to look for when matching amps and preamps. I never got any farther on this issue and still don't completely understand it.

"OK, I went back and tried to figure out what's important in matching amps and preamps and though I don't completely understand what to look for I think I found some clues. I had read some reviews of the Pass Labs Aleph 3 amp and its successor the Aleph 30. Due to the Aleph 3's "low voltage gain", it was not a good match for passive preamps (a preamp without active output). The Aleph 30's design included an increase in the voltage gain so it could be matched with not only passive preamps/controllers, but also with some low output TUBE preamps. I also discovered that some tube preamps like the Audio Research SP16L have low output levels presumably to lower the noise floor or to lessen audible "tube rush".

So, I think if you were going to match a tube preamp with a solid state (including single-ended like the Pass Labs) amp, you would need to check the amp's voltage gain and the preamp's output level. The remaining question is what are the threshhold values in amplifier voltage gain and preamplifier output level for a satisfactory match?

I'm not sure but I think I've found some clues. In the review for Audio Research's VS110 power amp and SP16L preamp (which you can find at stereophile.com in the archives), the reviewer tried the two components together and then substituted each one seperately into his system. The SP16L's output level (which the reviewer categorized as "gain") is 11.5dB. The "gain" rating for his reference preamp was 26dB. That appears to be quite a difference. When he put the SP16L in his system, he had some of the same volume problems that Pete noticed. No juice.

On the other hand, the VS110 amp from ARC had a gain of 28dB which the reviewer said was slightly higher than average, but he didn't say what average is. Therefore, the SP16L performed much better with the VS110. The preamp's lower gain was apparently for the purpose of lowering the noise floor, and its lack of juice was compensated for by the slightly higher than average gain from the VS110. So, I think you can conclude that if you were going to get the SP16L preamp for your existing amp, you should check your amp's voltage gain and make sure it's at least 28dB (or, slightly higher than average, whatever average is - maybe 26dB?)"

Great post Dean. System synergy is one of the most overlooked pitfalls in audio.

Bernd

[dean_martin]

Great post Dean. System synergy is one of the most overlooked pitfalls in audio.

Bernd

Thanks, Bernd. I saw your post on system synergy on the general board. I've become more aware of the care needed in matching components and speakers lately, but at a little lower price bracket than the examples given in your thread. I've got some leads on a pair of easy to drive bookshelf speakers to go with my new tube integrated. At the time the speaker manufacturer designed and built the model I'm interested in, it had a relationship with a tube amp manufaturer. I recently replaced a cd player with one that takes advantage of the characteristics of my tube amp. I've also picked out a moving coil cartridge that should sound right through tubes - should get the extension at the frequency extremes and detail that moving coils are known for but with a touch of warmth through the tube amp. Each component should compliment its associated gear.

[Bernd]

Thanks, Bernd. I saw your post on system synergy on the general board. I've become more aware of the care needed in matching components and speakers lately, but at a little lower price bracket than the examples given in your thread. I've got some leads on a pair of easy to drive bookshelf speakers to go with my new tube integrated. At the time the speaker manufacturer designed and built the model I'm interested in, it had a relationship with a tube amp manufaturer. I recently replaced a cd player with one that takes advantage of the characteristics of my tube amp. I've also picked out a moving coil cartridge that should sound right through tubes - should get the extension at the frequency extremes and detail that moving coils are known for but with a touch of warmth through the tube amp. Each component should compliment its associated gear.

Hi Dean,
Your 100% right with that. What integrated do you have now? I have completley moved away from pre/power to the believe that a realy good designed integrated will be the better musical performer.When I got the speakers I am using now,I used a Hybrid amp (Pathos Logos) on them and although the sound was good it was not how I wanted it. So I did some research and found out that the speaker manufacturer uses Valve amps to voice their Music speaker range. And then I had to know what Valve amp manufacturer and which model. So I got where I am now.
What Cartridge are you considering?

Have fun

Bernd

[dean_martin]

Hi Dean,
Your 100% right with that. What integrated do you have now? I have completley moved away from pre/power to the believe that a realy good designed integrated will be the better musical performer.When I got the speakers I am using now,I used a Hybrid amp (Pathos Logos) on them and although the sound was good it was not how I wanted it. So I did some research and found out that the speaker manufacturer uses Valve amps to voice their Music speaker range. And then I had to know what Valve amp manufacturer and which model. So I got where I am now.
What Cartridge are you considering?

Have fun

Bernd

I have the Jolida 202. It's a 40 watt EL34 based amp with plenty of power for my listening room. I'm still using the stock tubes and I'm in no hurry to tube roll. I was surprised it's so quiet. I was used to the little hiss that came through my speakers with the solid state preamp/amp combo I was using (you couldn't hear it while music was playing). From everything I had heard about tubes, I assumed I would have to adjust to background noise, but that's not the case. It's dead quiet which helps me hear things in more detail than before.

I finally decided on the Ortofon MC-X3 for my next cartridge (my first moving coil). It was a tough call between the Ortofon and the Denon 110 or 160 mainly because I have no place within 5 hours to even audition a cart. I would like to get one of the Denon's eventually.

[Bernd]

Hi,
As you found out a properly designed tube amp will not hiss. My system is all tube and dead quiet.
As for the cartridge I think the Ortofon is a better bet. The Denon's ,also many users like them, are an old design.
Have fun

Bernd