Mosfet vs. Bipolar revisited and the Belles 350A

I have always favored bipolar outputs with mosfet drivers until I ran into the Belles 350A. I stated this preference in a thread sometime ago. After listening to the 350A, I have to do an about face (at least with this amp.) The 350A uses 3 gain stages and operates almost entirely in class "B" with a very little of class "A."
I have heard a lot of amps but never one so neutral, transparent, reveiling and most any other attribute. It also has unbelievable bass control, pitch definition and lower transparency. No Mosfet haze here.
I have been using a Theta Dreadnaught 4-ch amp biwired. I must say, this amp IS better with my Vandersteen 3A Signatures. You can actually not use the subs(pair of 2wq's) and not really miss anything. I have not found this level of performance in this price range before($3495) I finally get to really hear these speakers do their thing.
I have adopted opinions over the 35+ years I have been playing with this stuff but I have never run across an amp that totally changed my way of thinking like this one. This is the overall best amp I have found (so far) driving the Vandersteen's.
I trust you meant to write either "low-level transparency" or "higher transparency", not "lower transparency"... :-)

Goes to show once again that we generalize based on technology stereotypes at our own risk. Glad to learn of your discovery and satisfaction - enjoy.
Does not matter what Transistors are used.It's all in the implementation and the synergy between components.

I have had both and have found that it's a synergy thing.At present I am using a B&K ST-202 that is very transparent.Before I had a Bi-Polar that could not drive Maggies correctly,but did great with box speakers.The B&K does both well enough to be satisfactory.There is no Mosfet Mist with the amp being forward Bias'd which I wish more amp manufactures would implement.That has been said to clear up the Mist associated with Mosfets.

Linearity is said to be better using Bi-Polars,but Ralph at Atmas-Sphere says otherwise and Gamut has done great in implementing them into his designs.

I am going to try another amp that has a Mosfet Pre-Driver stage and a Bi-Polar Output Stage .The Transistors will be made by Toshiba which are the same Trannies used in Mark Levs.This is real intresting as the LeAmps are only $400 a monoblock pair.At worst I will use them for Bass amps if I do not like the signatire in the Mids\Tweeter range.

Lastly the Power Supplies used have a great impact as to how good a design is.That is where it all starts!

The following is a Post I saved regarding Amp Designs!Its a good read.

Remember reading that a one benchmark about how good an amp is can be measured at how much power can be delivered when Halfing the Impedance rating. As an example lets say an amp is stated to deliver 200watts at 8ohms and then delivers 400watts at 4ohms then deliver 800wats into 2ohms.Does the ability to double it's rated output that way tell you anything about the amps ability besides being able to drive a wider range of speakers? TIA,ABEX

Actually, it tells you several things.

1. It tells you the designer was using his head while working, and recognizes the fact that nasty things like impedance drops, phase shifts, etc actually do exist, operate in real life like it or not, and attempt to modify the amp's performance into real world speakers, as opposed to lab test loads (usually a bank of high power resistors);

2. It tells you the power supply of that amp has been really well done, no skimping. No output stage can deliver real world power into real world speakers if it doesn't have an energy pool to draw that power from;

3. It tells you the output section in particular, but also the whole amp, has been conceived with proper capability to negotiate even very difficult loads, which gives you freedom to choose among speakers according to taste, and not to have to think about drive capabilities, and

4. It tells you the amp's performance, such as distortion and frequency response, will be modified very little by even evil loads, which is a hallmark of any good design.

As a sideline, it also tells you whoever designed it, was one competent designer and worthy of respect.

On the other hand, however important that is, it's not the only factor deciding on the overall quality of the sound. Let me put it this way - such an amp stands a better chance of sounding good than another without such capabilities.

This means less than perfect loads will not curtail the amp’s dynamics, and that it will in fact drive almost anything somebody decided to call a speaker.

I'd do more than that - I'd say power supplies are THE place to start. It's quite simple - the whole product rests on power supplies, without good power supplies, the rest is usually meaningless, and in any and all cases devalued.

The most common and sensible tweak of any product is modding the power supplies. No matter how poor it may sound, after that mod it will sound better, every time, never fails.

Of course, those are absolutes, and there is a relativity factor here as well. If you have to double the product's price to get a 15% improvement in sound, well, that's hardly rational, is it?

there are TWO things I'd say to you:

1. By all means, do start from the power supplies, and
2. Remember, it's all a balance, to have significant gains you need to mod at least a few things, never just one.

BTW, you found some good brains to pick; Audi has one of the best electrical arrangements in the entire car industry, in my view, better than Mercedes-Benz and BMW. Your paw-in-law sure knew what to pick, kudos to him.
The Belles is a great amp for the price, he has always designed very good products but was not well known.
I am not a technician, so any analysis of the over 100 amps experienced in the past 30 years comes by hearing alone. I am part of the generation that only had bipolars, and a few exotic variations in the 70s, and every year someone had "the" answer to improve their sound. My first "breakthru" amp was a Tandberg 3006. I did not know why, but it stayed in the system for 5 years, even as I was actively trading for profit other amps. At some point, the suggestion of "mosfet" as the reason was given to me. So, I tried that line. Hitachi, B&K, Muse - had strengths and irritations. They went, the Tandberg - three models over a 10 year period - kept returning to my system.
I did get the unexpected opportunity to possess an OCM200, which is a Belles design. Normally $1400 amps would be out of my range, but this one came cheap, so I listened. I would say that I have never had any amp that overall as a full range amp I would rate superior to the OCM200. Everything the previous writer said about his Belles is dittoed for the OCM. If I was listening to a single speaker full range, the OCM200 would still be with me. It is only because of one of its STRENGTHS that I very reluctantly let it go. It has the slam, slightly elevated bottom octave energy of the Bryston line - a wonderful attribute. But, I use a satelite/sub system, and the bottom octave energy actually put too much low energy into the satelites. The synergistic effect was to bloat the 80 - 120 hz energy region in my room. No combination of crossover/equalization would solve the problem without breaking the seemless transition. Oh how I wanted to keep it, but I had to face the facts.
A Tandberg integrated amp - 3012 - now handles the satelites. The Tandberg is "normal" regarding bass - and normal is excellent without slam. From 100hz up, there is no loss of detail, depth, musicality using the Tandberg. I actually prefer the integrated over the Tandberg power amp. The front end controls also make fine tuning, and timbre changes - such as music versus movies - a snap. I have compared the Tandberg with CJ, new generation Adcom, Coda, Kinergetics, new generation Denon. The 20 YEAR OLD DESIGN of the Tandberg 3012 proves to me the point of design execution. I have stopped "auditioning".
While I have a slight preference for mosfets, I concur that design execution and system synergy are the most important factors in personal system satisfaction. But I had an advantage in being a heavy trader. As a heavy trader, you get to eliminate the bull, the marketing, the snob appeal, the reviewers, and judge the product for what it actually does. I can buy whatever I really want, yet I love the fact that my system is made up of no individual component with a market value of more than $350!!
But, so that my opinion my be lowered to its appropriate level, I confess to using anyones leftover interconnects and hardware store 12 gauge cord for the speakers. I cannot hear differences at this level, and it breaks my heart to read the ads listing $1200 of 1998 recommended component interconnects now for sale at $400. I am VERY glad that I do not hear at this level of resolution.
But that's another topic.
jrobin out.
I do hear differences,but as you I do not think any of my components are vastly expensive.With the exception of the amp and speakers nothing is over $400.

Price is relative when it comes to audio and I can put my system against things costing many times more without flinching.There are more variables that make a good system than what the final cost is.

Do not know how many times I have shaked my head after hearing some components costing alot more and not getting good results,but people buy things without knowing or doing research into what they are getting.

I look at speakers as musical instraments as well as furniture.Other components as appliances that must perform the best for the $$ I am willing to pay for them.

Some of my equiptment is 20yrs.+ old that is still reliable and is good enough for my taste.

I tend to do as the last couple of posters have done, I buy stuff and listen to it. That way, I know if it will please me or not. I also buy just for the opportunity to listen and then sell if I don't want to keep it.
Zaikesman, what I meant was that the amp has excellent lower frequency transparency. Some amps sound wonderful through the mids and highs with superb transparency but in the lower frequencies, they lose control and sounds become less distinct and jumbled sounding(less resolution and transparency.) You don't get that see through to a kick drum or bass.
The Belles has a damping factor of well over 1000. Maybe that is why the Vandersteen's thrive on this amp. My Theta never had the low frequency control of this amp. Also, since Vandy subs(2WQ) take on the sound of the amp, now they sound considerably faster.
Since this amp has not been well reviewed, I bought it as an unknown entity on a friends recommendation. I did see in Soundstage where the reviewer pretty much conveyed my same thoughts about the amp. I caught this review right after the tornado's pass by the coast, lightning struck my front yard pine and knocked out my big screen TV last night. (along with a few other things)
I have used several sizes and brands of bi-polar and MOSFET amps over the past 20 years. Smallest being 60wpc and the largest being 500wpc. I find that I prefer the clarity and speed my ears hear in a good MOSFET amp. The only bi-polar amp that has that clarity and speed that I've owned and listend to for some time (still a record in my system at 6 years) was a Bryston 2B-LP. I attribute this to the fact that it only has one pair of output devices per channel. So no parallel matching of devices is required. I also think that the biggest contributing factor to the MOSFET sound is not the output device, but that most MOSFET designs use only two stages of gain and very little feedback. Fewer devices in the 2B-LP and two gain stages in MOSFET designs. Fewer devices seem to provide the best clarity and speed. Tops in these categories has been the BAT VK-200. Again, two gain stages, no global feedback and a MOSFET design. Am going to have to listen to the new VK-250 to see if the Russkies at BAT have been able to maintain these attributes in their newest design. Will also have to search out a Belles 350A to listen to after the good things I read about it.
Abex, do you think we will ever see the LeAmp 2s?? I have a pair on order but have lost patience and am thinking about canceling. Disgusting how M. Barnes mislead everyone on shipping this amplifier.

After reading Bigtee's post I may opt for a Belles 350A myself. Its a bit more money but it is also available and proven.
Disclaimer: I am a Power Modules Dealer.

It seems to me that Dave Belles is finally starting to get some of the recognition that he deserves. ALL of his products represent one of the biggest performance to price ratios in all of high-end audio. The Belles designs are the epitomy of how a MOSFET amp can/should sound, IMHO. At the very least, anyone that is on the hunt for a new preamp, amp, or integrated should consider the Belles products (before spending more money on another product that very likely will not be any better).

Best Regards...Mike - Father & Son Audio
I own a 350A, so I am completely neutral. HA!
Really, when people talk about the Levinsons, Krells, et al, I can almost smile to myself and feel that I have a secret. But for Dave's (Belles) sake, I should adopt a different viewpoint. This is one helluva amp. It is exactly as described above. It has the most control over speakers, that I have EVER heard, and at any price. Plus, as I stated on another thread, I can identify who's amp is which, by its inherent "sound". This amp is also the most "neutral" that I have heard. What an amazing accomplishment for a $3500. amp!
Plus I am told that the new 150 and 150 mono's are even better in some ways. That is hard to imagine. I am looking to buy the mono 350's so may sell my 350 to do that.
This is truely a magical, neutral amp. If you have a dealer, take one home and try it for a few days. It is an epiphany, for not much money comparitively speaking.
Thanks for noticing Belles, I just started a thread asking when Belles is going to get the regognition he deserves...I think it is starting to happen.
personally i've never liked bipolars, as they sound a little synthetic / etched (typical SS sound) and lack liquidity, though they do exhibit amazing control.

mosfets ala the belles 350 completely bridge the gap in control w/ bipolars, though mosfets in less than class A (which the belles is) tend to have a warmth that smoothes over things, while lacking the liquidity known for a good tube amp.

perfect world: high power /current class A (to 100+wpc) mosfets. haven't seen it, but i am looking---the lamm hybrid looks nice--100wpc class A mosfet if i recall correctly, and lamm seems to make a decent product.