Not another bi-amping question?!?!?

[eknuds01]

Yeah, yeah,yeah I know I haven't posted in like 62 years BUT I have started to make some small changes to my system (I just ordered some Anti-Cables!) and I am looking to, at some point, add a tube amp to the panels of my Aerius i speakers.

Here's my question:

Is there a minimum on the power output needed to power the panels? My room isn't huge nor do I listen at very loud levels. I have poked around the forum using the search feature and also did some looking elsewhere and I have seen amps with rated outputs as low as 35 watts/channel. Would anyone recommend anything lower than this? Is there another metric that is more useful other wpc?

I plan on using a beefy SS amp on the woofers, but I don't want to buy a tube amp that is simply not up to the task. I am also not looking spend much more than $1200 for a tube amp, so if anyone has some suggestions that would be very helpful. It seems that there are so many options but tube amps are expensive and one can easily drop 2, 3, or 4 thousand on a decent amp.

I have been looking at Primaluna amps as well as Jolida. Those two brands seem to be on the 'low end' with respect to tube amplification. I don't I am going to find much from ARC, Cary, CJ, etc in my price range even on the used market.

 

[Bernard]

eknuds, welcome back! Your name rang a bell, so I checked my system thread....do you still have that ARC SP 9, and have you changed the volume pot for a stepped attenuator? If you still have it but have not changed that pot, you're missing a lot.

 

[eknuds01]

eknuds, welcome back! Your name rang a bell, so I checked my system thread....do you still have that ARC SP 9, and have you changed the volume pot for a stepped attenuator? If you still have it but have not changed that pot, you're missing a lot.

Yup, that's me Bernard!

Is this change very easy to accomplish?

 

[Rich]

Biamping the older MLs with tubes on the panels and SS on the woofers is an excellent way to go. Hard to answer the question about minimum needed wattage. Tube amps tend to exert more control over the panels than SS for a given wattage. But lots of variables will determine what the minimum wattage is that you need. Personally, I wouldn't go with less than 200 wpc SS on the woofers and 100 wpc tube on the panels. You could probably easily get away with less on the panels, but dynamics and overall presentation may suffer at higher volumes or complex passages. A lot depends on the build quality of the amp. I would take a beefy well-built 50 wpc amp over a cheap poorly-designed 100wpc amp any day. Of the two you mentioned, I would favor the primaluna. The one time I heard a jolida powering an ML panel (Vista), the sound was over-the-top euphonic. Not to mention I think primaluna has a better reputation for build quality.

One other thing. Make sure you match the voltage gain between the SS amp and the tube amp or you will get a volume difference between the woofers and panels. If you can't get amps with the same gain spec, you can always put an attenuator on the amp with the higher gain and match them manually.

 

[twich54]

Erik, you know my opinion on 'bang-for-the-buck' when it comes to tube amps ........... Rogue

 

[Bernard]

Yup, that's me Bernard!

Is this change very easy to accomplish?

If you use a DACT stepped attenuator ($219 from PartsConnexon) it's very easy to accomplish:
-Unsolder the six potentiometer terminals from the board
-Unscrew the knob from the pot
-Unscrew the pot and remove it
-Increase the size of the hole slightly with a round file
-File a notch on the edge of the hole to stop the control from rotating
-Mount the control and screw the knob onto it
-Solder six wires from the board to the control. The solder lugs on the control are in the same positions as the original pot.

 

[eknuds01]

Biamping the older MLs with tubes on the panels and SS on the woofers is an excellent way to go. Hard to answer the question about minimum needed wattage. Tube amps tend to exert more control over the panels than SS for a given wattage. But lots of variables will determine what the minimum wattage is that you need. Personally, I wouldn't go with less than 200 wpc SS on the woofers and 100 wpc tube on the panels. You could probably easily get away with less on the panels, but dynamics and overall presentation may suffer at higher volumes or complex passages. A lot depends on the build quality of the amp. I would take a beefy well-built 50 wpc amp over a cheap poorly-designed 100wpc amp any day. Of the two you mentioned, I would favor the primaluna. The one time I heard a jolida powering an ML panel (Vista), the sound was over-the-top euphonic. Not to mention I think primaluna has a better reputation for build quality.

One other thing. Make sure you match the voltage gain between the SS amp and the tube amp or you will get a volume difference between the woofers and panels. If you can't get amps with the same gain spec, you can always put an attenuator on the amp with the higher gain and match them manually.

Rich -

Could you expand on this some more? I think a 100W tube amp (in a general sense) is likely out of my price range. I don't disagree with the 100 wpc metric as my 'gut feeling' is that 100 wpc is a nice round number and it will likely serve me well.

With respect to tube amps, what is in them that you like, or don't like? What do you like to see?

 

[Rich]

Rich -

Could you expand on this some more? I think a 100W tube amp (in a general sense) is likely out of my price range. I don't disagree with the 100 wpc metric as my 'gut feeling' is that 100 wpc is a nice round number and it will likely serve me well.

With respect to tube amps, what is in them that you like, or don't like? What do you like to see?

Good question, and it's kind of hard to answer as I'm just not overly familiar with the amps in your price range and what they offer. My first thought is get one with a beefy power supply. Next thought is quality of internal components, especially the capacitors. I don't know how you judge this except by reading between the lines of a lot of reviews. It's not necessarily going to show up on spec sheets. The best you can do is go with a brand known for higher quality. That's CJ, ARC, Mac, Rogue, Manley, and a few others. You may do better for the money buying used than new. Personally, I would avoid the Jolidas and Vincent's and similar.

I think a Rogue Atlas or Atlas Magnum would fit your needs quite well, though it's slightly beyond your price range. If you could find a used Magnum that would likely be in your price/performance sweet spot.

My only personal experience with owning a tube amp is with my CJ Premier 140, and it exerts iron-clad control over the panels of both my Ascents and Summits. I have heard lots of other brands in various setups, but this is the only one I've owned. So I'm afraid my experience is limited with the price range you are shopping in.

 

[eknuds01]

Fair enough. It probably goes without saying that ARC, BAT, CJ, Levinson, Pass, etc are more expensive because they use very high quality components. They aren't just expensive for the sake of being being expensive, or 'upscale.' I was actually looking at Rogue amps the the night and I know that Dave is a big, big fan of that brand. I've listened to Dave's system and he has excellent taste! Rogue is worth another look for sure.

 

[Bernard]

I used to drive my Logans with a 50-watt Copland tube amp, and they sounded great, but didn't have any guts in the bass. I borrowed a SS 100-watt Copland amp, which had the guts I was looking for, but failed to move me elsewhere; it sounded fine, but not as alive as the tube amp. Things fell into place when I got 110-watt ARC tube monoblocks. So tubes do it for me.

That said, there are lots of people here who swear by Pass, Plinius, etc. You just have to suck it and see. In that vein, why don't you consider buying used. That way you can resell the stuff without major financial impact.

 

[eknuds01]

I used to drive my Logans with a 50-watt Copland tube amp, and they sounded great, but didn't have any guts in the bass. I borrowed a SS 100-watt Copland amp, which had the guts I was looking for, but failed to move me elsewhere; it sounded fine, but not as alive as the tube amp. Things fell into place when I got 110-watt ARC tube monoblocks. So tubes do it for me.

That said, there are lots of people here who swear by Pass, Plinius, etc. You just have to suck it and see. In that vein, why don't you consider buying used. That way you can resell the stuff without major financial impact.

I am considering buying used but finding 75 wpc or 100 wpc tube amps (again I want to bi-amp using my Sunfire on the woofers) is not easy. Well, it IS easy if you don't mind parting ways with $2000-$3000. I am hoping to find a 30-50 wpc tube amp (panels only) that's in the $1000-$1200 range. You'd be surprised how little is out there in that range however.

 

[Rich]

Things fell into place when I got 110-watt ARC tube monoblocks. So tubes do it for me.

Bernard, have you tried biamping the SL3's with the ARC on the panels and SS on the woofers? I found that when I went from using just the CJ 140 to power my Ascents to biamping them with 200 wpc class D monoblocs on the woofers, the sound improved tremendously. Especially at higher volumes and with more complex music. It was quite a noticeable improvement.

 

[Spike]

Could you expand on this some more?

Here's my post on this subject of beefy/stable power-supply for tube amp driving electrostatic panels.
Tube amp driving ML panels

Is there another metric that is more useful other wpc?

Yes, please read this ESL Amp article from Sanders Sound where voltage stability is more important than WPC for electrostatics.
ESL Amp White Paper

I have been looking at Primaluna amps as well as Jolida.

Between these 2, definitely PrimaLuna. There has been issues with quality control for Jolida, where it's hit-or-miss with regards to the units you get. Rogue and PL should be at the top of your list. I'd also mention the AES SixPacs, but they don't come up too often on A'gon nowadays. Be very patient and your ears will thank you.

 

[Pneumonic]

Yeah, yeah,yeah I know I haven't posted in like 62 years BUT I have started to make some small changes to my system (I just ordered some Anti-Cables!) and I am looking to, at some point, add a tube amp to the panels of my Aerius i speakers.

Here's my question:

Is there a minimum on the power output needed to power the panels? My room isn't huge nor do I listen at very loud levels. I have poked around the forum using the search feature and also did some looking elsewhere and I have seen amps with rated outputs as low as 35 watts/channel. Would anyone recommend anything lower than this? Is there another metric that is more useful other wpc?

I plan on using a beefy SS amp on the woofers, but I don't want to buy a tube amp that is simply not up to the task. I am also not looking spend much more than $1200 for a tube amp, so if anyone has some suggestions that would be very helpful. It seems that there are so many options but tube amps are expensive and one can easily drop 2, 3, or 4 thousand on a decent amp.

I have been looking at Primaluna amps as well as Jolida. Those two brands seem to be on the 'low end' with respect to tube amplification. I don't I am going to find much from ARC, Cary, CJ, etc in my price range even on the used market.

Fundamentally, what you desire is an amp that has a power supply that can supply enough output current to properly drive the panels during low impedance conditions and swing enough voltage to play them, to your desired volume level, without clipping and introducing audible level of distortion.

Unfortunately, short of sticking an oscilloscope onto the amp's output and looking for chopped off voltage peaks, it is impossible to say, for certain, if the amp employed is up to the task at hand.

As for other metrics to consider. Ensure the chosen amp stays well damped and has suitably low output impedance. This will help ensure you won’t encounter a variable frequency response once connected to a passive crossover. In practice, any capably designed solid state amp will not have this issue. Transformer coupled tube amps are another story however since they will not have a linear frequency response due to impedance mismatch issues. As well, you should ensure the chosen amp can drive the capacitive load that the panel presents and not become unstable and oscillate.

 

[Bernard]

Bernard, have you tried biamping the SL3's with the ARC on the panels and SS on the woofers? I found that when I went from using just the CJ 140 to power my Ascents to biamping them with 200 wpc class D monoblocs on the woofers, the sound improved tremendously. Especially at higher volumes and with more complex music. It was quite a noticeable improvement.

I have always intended to, but have not done so yet. I should have when I had the Coplands.

Something to try when funds permit.

 

[Rich]

I have always intended to, but have not done so yet. I should have when I had the Coplands.

Something to try when funds permit.

Bernard, you have to try this. Even with an inexpensive SS amp on the woofers. I used a pair of Outlaw Audio Class D 200 wpc monoblocs that only cost like $350 each on the Ascent woofers and it made a huge difference. Freeing up the tube amp from woofer duty allows it to excel at what it does best. It exerts complete control over the panels with headroom to spare, and the SS amps do a great job controlling the woofers. Dynamics, transient response, separation of instruments in complex pieces -- everything gets better! I get the same effect now with the Summits as they are internally bi-amped. But I still remember what a huge difference it made when I had the CJ on the Ascents. Highly recommended.

Also -- kudos to Spike and Pneumonic for a couple of excellent posts answering O.P's questions far better than I was able to. Great stuff!

 

[Peter Hogan]

Biamping the older MLs with tubes on the panels and SS on the woofers is an excellent way to go. Hard to answer the question about minimum needed wattage. Tube amps tend to exert more control over the panels than SS for a given wattage. But lots of variables will determine what the minimum wattage is that you need. Personally, I wouldn't go with less than 200 wpc SS on the woofers and 100 wpc tube on the panels. You could probably easily get away with less on the panels, but dynamics and overall presentation may suffer at higher volumes or complex passages. A lot depends on the build quality of the amp. I would take a beefy well-built 50 wpc amp over a cheap poorly-designed 100wpc amp any day. Of the two you mentioned, I would favor the primaluna. The one time I heard a jolida powering an ML panel (Vista), the sound was over-the-top euphonic. Not to mention I think primaluna has a better reputation for build quality.

One other thing. Make sure you match the voltage gain between the SS amp and the tube amp or you will get a volume difference between the woofers and panels. If you can't get amps with the same gain spec, you can always put an attenuator on the amp with the higher gain and match them manually.

This is incorrect, SS amps have much better control of the panels. The value that matters is damping factor, which is the speaker impedance divided by the output impedance of the amplifier. SS amps, unless very poorly designed, will have a much lower output impedance than a tube amp has, typically 10 to 100 times lower.
Where the tube amp has an advantage is in the distortion spectrum, SS amps tend to have their distortion on odd harmonics (3rd, 5th, etc.), which have a very harsh sound...tube amps tend to have more even order distortion (2nd, 4th, etc.), which sounds more 'musical'...many musical instruments also produce even order harmonics when played.

 

[Rich]

This is incorrect, SS amps have much better control of the panels. The value that matters is damping factor, which is the speaker impedance divided by the output impedance of the amplifier. SS amps, unless very poorly designed, will have a much lower output impedance than a tube amp has, typically 10 to 100 times lower.
Where the tube amp has an advantage is in the distortion spectrum, SS amps tend to have their distortion on odd harmonics (3rd, 5th, etc.), which have a very harsh sound...tube amps tend to have more even order distortion (2nd, 4th, etc.), which sounds more 'musical'...many musical instruments also produce even order harmonics when played.

Technically, you are correct. I should have said tube amps tend to sound better on the panels than SS at a given wattage (particularly at lower wattages). Due to the capacitative load presented by the panels, amps with a high damping factor tend to sound awful on an electrostatic panel. Given a 100 watt amp, I would choose tube over SS to power my panels every time.