Q: Bi-Amping

[ralflar]

My searches for this topic here have been unsuccessful. Perhaps this is so because I did not come up with the right search terms. Apologies if this should be so. Bear with me in this case. As you may have concluded from my previous post, I am in the market for decent 2 channel amplification to replace that of my receiver.

My question to those of you who did experiment with bi-amping, and went back to normal, is: why was that?

And to those who prefer bi-amping, which amps do you use?

My own experience with bi-amping is positive. I realize that this may be so because I am using an inferior receiver. However, there are posts in another forum by users who replaced their bi-amped setup with a supposedly superior mono-blocked setup of the same brand (Arcam P1), and were disappointed. What is your experience?

 

[Spike]

My searches for this topic here have been unsuccessful. Perhaps this is so because I did not come up with the right search terms. Apologies if this should be so. Bear with me in this case. As you may have concluded from my previous post, I am in the market for decent 2 channel amplification to replace that of my receiver.

Try searching for keyword "bi-amp" in posts by "Spike" (yours truly)

And to those who prefer bi-amping, which amps do you use?

AES SixPacs on top, powering the panels. Classe' Audio CA-300 powering the woofers. Wonderful midrange and highs from the combination of triode tubes and electrostatic panels, combined with the solid-state control of the woofers.

Spike

 

[Rik_Rankin]

My searches for this topic here have been unsuccessful. Perhaps this is so because I did not come up with the right search terms. Apologies if this should be so. Bear with me in this case. As you may have concluded from my previous post, I am in the market for decent 2 channel amplification to replace that of my receiver.

My question to those of you who did experiment with bi-amping, and went back to normal, is: why was that?

And to those who prefer bi-amping, which amps do you use?

My own experience with bi-amping is positive. I realize that this may be so because I am using an inferior receiver. However, there are posts in another forum by users who replaced their bi-amped setup with a supposedly superior mono-blocked setup of the same brand (Arcam P1), and were disappointed. What is your experience?

Why not just get a decent 2 channel amp and bi-wire. If you are on a budget, an NAD might be a good choice. If you want a a great all in one unit, the Linn klassik is excellent. Of course if you can afford it, A Mac or Rowland amp is also a good choice

 

[miljac]

Why not just get a decent 2 channel amp and bi-wire. If you are on a budget, an NAD might be a good choice. If you want a a great all in one unit, the Linn klassik is excellent. Of course if you can afford it, A Mac or Rowland amp is also a good choice

I have an integrated Mac and having added a separate amp for the bass did make a considerable difference (for the better).

HTH

 

[Spike]

Why not just get a decent 2 channel amp and bi-wire?

Good question. I'll try to give an account of my journey and how I ended up with bi-amping my ReQuests. I started out with a tubed ARC-LS7 minimalist linestage, Classe' CA300 driving the ReQuests via MIT Terminator2 biwires. The front end source was CAL Delta/Sigma transport, tubed DAC combination. While this system was very musical, I felt that this system was a bit too polite, lacking immediacy in the musical attacks and the airiness of the long decay. At this point, I went through a long period of auditioning many amplifiers in system looking for the perfect match. The amplifiers range from all tubes ARC VT100 & 200, to class-A Llano, and Pass Aleph series. Going from Classe' (class AB) to class-A solid-state made a noticeable difference in terms of immediacy. There was a bit more airiness with the slightly longer decay. Going to the all tube ARC units, the sound opened up quite a bit more with smoother, liquid midrange, lots of airiness. The bass was a tad bit deepeer but more...loose. Hmm, let's see now: sound improved when I reduce the part counts going from class-AB to a 2-stage class-A of Llano and Pass. Further improvement was realized by going to a simpler circuitry of tubes with a good power-supply section. I was set out to see what is possible if we can reduce the part counts even further by going to triode configuration instead of ultra-linear. In went the AES SixPacs monoblocs to power the panels, complemented by the Classe' pulling bass-duties. Whoa, HUGE difference on the mids and highs. There's something to be said in favor of maintaining the purity of the original signal, especially in the all critical midrange and high frequence range. Next up, the ModWright SWL linestage replaced the ARC LS7 and voila, the transformation is complete, given the allowable budget. In the distant future, I may upgrade the SixPacs to Cary 805 Anniversary, and the Classe' to Pass Labs, but that's another story to come...
The rationale behind my bi-amp configuration? Maintaining the original signal by keeping the part counts that the signal has to go through to a minimum. This goal can only be achieved with lower powered amplifier. In my case, 50 watts per channel of push-pull triodes suffice for the panels.

Spike

 

[A.N.]

i'm bi-amping my aerius i with 2xlinn lk280.

not tried running a single 280 tho', as bi-amping the ml's sound great already, and, as i understand, having 2 power amps really grips the dynamics of the speakers.

 

[ralflar]

Spike,

Your system looks really nice, especially with those tubes glowing in the dark! Nice combo and thanks for the search hint. I spent a long time reading various of the threads found that way. Good info, specifically "Bi-amping Aerius i", "Biamp Top/Bottom Balance", and also attyonline's "Passive Biamping" threads.

Your rationale of using a tube for the panels and solid state for the woofers makes a lot of sense. But I am somewhat reluctant to use two different types of amps in a bi-amp configuration with my Aeon is, however. The crossover frequency between woofer and panel is rather high, 450Hz, and integration issues already exist because of that. I am concerned that bi-amping with tubes up, transistirs down would only emphasize those integration issues. The crossover frequency of the Requests is probably lower, though.

 

[ralflar]

Why not just get a decent 2 channel amp and bi-wire. If you are on a budget, an NAD might be a good choice. If you want a a great all in one unit, the Linn klassik is excellent. Of course if you can afford it, A Mac or Rowland amp is also a good choice

Well, I am not sure myself which way to go - bi-amp, or standard 2-channel or mono blocks. Decent 2 channel amplification, as you suggest, is definitely on my shopping list. I like NADs except for their battleship gray and single voltage power supplies.

While I grok how bi-amping can improve performance, and know that it works very well with my current cheapo amps, I fail to see how bi-wiring could have any benefits. I should probably try it anyway, just because I can and to hear if it does make a difference or not. But I doubt it.

As for my budget, I do not intend to spend more than 4k$ this time around... For that money I could get e.g. two Arcam P1 mono blocks or 2 Arcam P35 stereo amps. The latter can be set into mono mode for vertical bi-amping without Y adapters. I am looking at other makes and models also.

 

[ralflar]

Perhaps I should bring my original question more to the point:

What, if any, sonic disadvantages are inherent to bi-amping, in your experience?

 

[JonFo]

Perhaps I should bring my original question more to the point:

What, if any, sonic disadvantages are inherent to bi-amping, in your experience?

As I both bi-amp and externally crossover, I can help.

The main disadvantage is gain control. This needs to paid attention to, as balancing the panel to woofer across the dynamic range is important.

If you use an amp on the panels that runs out gas well before the woofer amp at high volumes, the 'tilt' of the sound will be very different depending on your volume setting.

Mixing and matching amp topologies is fun, but also needs to be done carefully, otherwise there will be frequency response abberations that will be audible as compared to a single toplogy driving the entire speaker. Although, this is part of the reason why mix-and-match between tubes and SS is popular, as the 'sound' of tubes can be leveraged on the panel, yet retain good control of the woofer with an SS amp.

Personally, I use same brand, same topology, but different ratings for panels and woofers. But I also very carefully gain match (with calibrated measuring rig) with external devices to ensure I have good balance at all SPL's.

So effort and complexity are the biggest drawback. But on the upside, it sounds much, much better ;-)

 

[ralflar]

Thanks for the explanation, Jonathan. Would you say that gain matching is required even when the same brand and model amps are used in a passive bi-amp setup?

What kind of equipment is needed in order to achieve a good level match? I have a SPL meter, and could probably find a way to play back white or pink noise - would that suffice.

 

[JonFo]

Thanks for the explanation, Jonathan. Would you say that gain matching is required even when the same brand and model amps are used in a passive bi-amp setup?

What kind of equipment is needed in order to achieve a good level match? I have a SPL meter, and could probably find a way to play back white or pink noise - would that suffice.

Hi raflar,

If using exact same brand/model, then likely no, but still worth checking.

Use of a basic SPL meter and processor (or test disc) sourced pink noise is a valid test for match. However, just make sure you take multiple samples from around the room. Since woofers will be more impacted by room modes, you would not want to compensate for having had the bad luck of measuring in a null (or peak) in the room.

As to what devices to use, for gain matching, I’d go down this list:

- try and find amp models with gain controls already in them
- use a passive, high-quality line-level gain control (make sure impedance match is good) between the processor and amp input.
- Use an active component if your amp has balanced in’s, this allows going from line-level to full balanced and also gives gain management. In my rig I use ART CleanBox and Behringer MX882’s as gain management tools
- If using external crossovers, most have gain control per output channel


Finally, not that I recommend this, but here is an example of how crazy one can get in terms of multi-amping and external crossovers. This guy didn’t know when to stop:

 

[twich54]

Well, I am not sure myself which way to go - bi-amp, or standard 2-channel or mono blocks. Decent 2 channel amplification, as you suggest, is definitely on my shopping list. I like NADs except for their battleship gray and single voltage power supplies.

As for my budget, I do not intend to spend more than 4k$ this time around... /QUOTE]

Having been down the same road your on right now I couldn't be happier than I am with my Plinius SA-102( yes this is the umpteenth time I've said this). given your max budget of 4k this would certianlly be doable in the in the used / demo area. Are their better amps out there ? pobably yes, but at it's price point it's the best I have heard to date and I suspect I'm not the only one who feels this way.