Ideal Pre Amp for Bryston 3B ST or 4B SST 2

IMHO there is no "ideal" preamp for Bryston amps.

Now I have had a few tube preamps (both balanced and single ended - Hovland, Rogue, Lamm) that have worked well with Bryston amps but would suggest that Audio Research products could get you what you are looking for (given your desire for balanced connections). I currently own an ARC LS-26 that does a great job with my Bryston amps.

An alternate choice would be to buy a used BP-26 with the new full size power supply and try that out. I can personally attest that I have found that to be a better preamp set-up than a BP-20 when matched up to a Bryston amp.

You might want to make the decision on the amp first as the SST2 series is quite different that the ST version and in the end could play a significant part in which preamp you ultimately end up with...

Yes you are correct Bryston pre amps are somewhat lacking.I owned Magnepan 1.6's powered at different times by 3B,4B, and 14 BSST's series amps in concert with an Audio Research LS 15 and later a 26.It was all good,great synergy between the trio.

I am using the Cary SLP 05 with my 28BSSTs which is a very nice combination.Several years ago I had the 3BST's with the BP-20 and thought that it was also an excellent match. I think Bryston pre-amps are over shadowed by their amp more then the Pre-amps are "lacking"...

In the end, I think tube pre-amps are a wonderful compliment to the robust Bryston energy..

asking someone else what equipment sounds good is like asking someone what painting looks good: you end up with someone else's perspective with no idea of whether you would think the same. i've had a bryston 4bst and bryston bp-20 for a dozen years and to my ears there is nothing wrong with this equipment. but that doesn't mean that someone else will think that it sounds good. it's all about individual preferences and little more.

some people like tubes because they presumably produce a "warm" sound. the problem is, that "warmth" is signal distortion. but if a distorted signal sounds good to you, then that's the way that you should go.

so the real question you should be asking yourself is whether you like the sound of your equipment, not whether someone else says whether or not "the best" (whatever "the best" means). but if you are going to ask the opinions of others the operative phrase to always keep in mind is "caveat emptor" because you have no idea as to whether the speaker acutally knows what he is talking about. i frequently read authoritative-sounding comments on this forum that are factually ridiculous. so be forewarned.

The ideal preamp for your Bryston amp is a Bryston preamp. They were designed to work together by brilliant engineers.

12-07-10: Rrog
The ideal preamp for your Bryston amp is a Bryston preamp.

there is not particular reason why this statement should be true: to the amplifier, a signal is a signal. there is no technical reason why a bryston amplifier will work better with a bryston preamplifier. i don't believe this "synergy" business in anything other than a subjective context. but as with all subjective concepts, different people will have different opinions.

Lots of choices but mostly around AR...no surprise as they seem to have one of the best reputation in the business. Thank you. The opinions are appreciated, wish I could simply experiment with a new AR Pre and test my curiousity...perhaps if the lottery numbers are those on my weekly ticket.

The Bryston Pre is not bad I only was enquiring since I got a chance to hear the Maggies 1.6 played through a Tube preamp and SS Amp and the sound was truly enjoyable. To explain the effects, it was as if the music enveloped you versus punching you in the face.

Once again thank you for your input. Very much appreciated

12-07-10: Bob_reynolds
Paperw8, I agree with your comment regarding synergy in general, but proper impedance matching between a preamp and amp is a very real concern when mixing products from different manufacturers. It typically involves mixing different technologies - solid state and tubes.

you raise a good point about the need to be concerned with matching between tube devices and solid state devices. i don't follow the tube scene but i am aware that there can be issues with interfaces the two technologies. as i understand it, signals from tube preamplifiers can have dc components that can be a problem with some solid state amplifier inputs that don't have dc-blocking capacitors in the input path. i don't know that sticking with the same brand provides any specific advantage, but in any event, if someone intends to mix technologies it's always a good idea to check for potential compatibility problems. the main problem that i would expect is that you might be limited to using single ended amplifier inputs if you use a tube preamplifier.

as to the idea of impedance matching between preamplifiers and amplifiers, that is not done to my knowledge (i am taking "impedance matching" to mean the output impedance of the preamplifier is equal to the input impedance of the amplifier - and my comments refer to solid state only). preamplifiers and amplifiers typically have high input impedances because what you want to do is to transfer a voltage (you're not really trying to maximize power transfer between the preamplifier and the amplifier).

one notable exception is krell cast inputs, which tend to be low impedance. but the point of the krell cast system is that you are transferring a current from one device to another, so you don't want amplitude of the transferred current to be limited by a high input impedance. according to krell, the idea of waiting as long as possible before converting the current into a voltage results in superior sound reproduction. i have never heard a krell cast setup so i can't comment on how well the system achieves its stated objectives.

Paperw8, Since you don't follow the tube scene try mating a Quad preamp with your favorite solid state amplifier and tell me how you like the sound.

Besides preamps and amplifiers matching electrically they must also match sonically. You can mix and match to your heart's content and come up with all kinds of sounds which I have done countless times, but whenever I mate like brands of preamps and amplifiers there is a rightness to the sound that is never achieved with the mixing and matching.

This is why I say a Bryston preamp is idea with a Bryston amp. Unless you don't know the difference. Then it really wouldn't matter.

12-08-10: Rrog
Paperw8, Since you don't follow the tube scene try mating a Quad preamp with your favorite solid state amplifier and tell me how you like the sound.

you can make reasonably deterministic statements about whether different components are electrically compatible. but you can not make deterministic statements about what sounds good. you may be right that i might not like the way a given tube preamplifier and solid state amplifier pairing might sound, but since i haven't heard one, i can't say for sure. even at that, such a system might sound good to someone else.

i happen to be fine with the sound of my bryston preamplifier/amplifier configuration, but someone else might use a non-bryston preamplifier and bryston amplifier and find the sound of that system preferable. by and large this audiophile stuff is mostly about personal preferences: you can't tell me what my personal preference "should" be any more than i can tell you what your personal preference "should" be. that's just the way that it works...

I'm using a 3BST with an ARC SP16 in conjunction with a SCE Harmonic Recovery System device that helps with impedance matching between amp/preamp. These are driving Vandersteen 3A Sigs and I am enjoying the sound. When my finances are right I'd like to get an ARC power amp, maybe a 100.2,D300, D400mkII or 300.2. The ARC amps have a 150k input impedance which would mate perfectly with the SP16.
The SCE HRS is no longer made, but there have been discussions about it here and elsewhere. I'ts an option if impedance matching is an issue. Some may not like the idea of another box, more cables, etc in the chain. I have seen them come up here on A'Gon from time to time. If anyone out there has experience with this device, please chime in on your observations.

12-08-10: Bob_reynolds
Some manufacturers of both solid state and tube gear will ensure that the input impedance of their solid state amps is high enough to mate well with one of their tube preamps. Thus, sticking with the same manufacturer has it's advantages.

i can believe that...

12-08-10: Bob_reynolds
Of course, some solid state amps are designed with a high enough input impedance to mate well with any kind of preamp. You'll notice that Bryston amps have a usefully high impedance on their unbalanced inputs and a less useful impedance on their balanced inputs.

i did notice that input impedance for balanced inputs is lower than that for unbalanced inputs in bryston amplifiers. do you know why it is that the input impedance for the balanced inputs is lower than the input impedance for the unbalanced inputs?

I'm going along with Bob reynolds, You may not call it synergy, but when a designer designs both an amp and preamp, he matches them exactly as he see's they should be, no voltage or impedance mis matches, similar idea's and normally the same brand of gear does quite well together. I can't say if it is synergy or not, but it works. Of course that doesn't mean other things won't work together, i'm just putting in a reason why Bryston just might work well with another Bryston. I haven't listened to them, but I'm told Brystons latest generation pre's are quite good.
As far as another pre that won't cost a mortgage??? In july I picked up a New Coda, bought directly from Coda, they discounted it nicely and it is a very nice piece of equipment, worth looking into. Good Listening, Tim

I did notice that input impedance for balanced inputs is lower than that for unbalanced inputs in bryston amplifiers. do you know why it is that the input impedance for the balanced inputs is lower than the input impedance for the unbalanced inputs?

I took a look at the schematic for one of their amplifiers, the 3BSST, shown here. (Bryston is the only current manufacturer I am aware of that has schematics for many of its products on its website). The amp has an input impedance spec of 50K for the unbalanced inputs, and 20K (described as "10K per leg") for the balanced inputs.

The input stage active device, referred to on the schematic as a DOA68, I believe is an op amp that is custom made for Bryston. In the unbalanced input configuration it is used as a non-inverting amplifier with a gain of either 1 or 2, selectable via a switch. Circuits in which op amps are used in a low-gain non-inverting configuration have extremely high input impedance, in this case such that the overall input impedance of the circuit is essentially determined by the 49.9K resistor R6.

In the balanced input configuration, the op amp is of course used as a differential amplifier. That kind of op amp configuration has a much lower input impedance than a low gain non-inverting configuration.

The overall input impedance in the balanced mode is essentially determined by a combination of the various 20K resistors you will see on the schematic. The input impedance of the Channel 1 inverting leg is equal to the parallel combination of R1 and R1A, which is 10K.

In the high gain (1V) configuration, the input impedance of the non-inverting leg is equal to the parallel combination of R2 and R2A (10K) in series with R4 (20K) resulting in an overall input impedance of 30K.

In the low gain (2V) configuration, the input impedance of the non-inverting leg is equal to the parallel combination of R2 and R2A in series with the parallel combination of R4 and R5, resulting in an overall input impedance on that leg of 20K.

So the input impedance description for the balanced inputs of "10K per leg, 20K overall," I don't think is entirely accurate, but the higher input impedance on the non-inverting leg won't have any adverse effects, as I see it. It is common for differential amplifier stages to have unequal input impedances on the two legs.

I suspect that the reason the 20K resistors were not chosen to be significantly larger, such as 50K, is that in the differential amplifier configuration various non-ideal characteristics of the op amp itself, such as perhaps what are called input offset currents, as well its own input impedance, would then have become significant.

Regards,
-- Al

The DOA notation on the op amp symbol I believe is Bryston's Discrete Op Amp and not a custom IC.

Thanks, Bob. I hadn't been aware of that.

Best regards,
-- Al