[darkmoebius]

If I understand correctly, neither uses output transformers with the Moscode being closer to a traditional OTL than the Butler. There's a substantial price difference with the Moscode costing 30% more. But, the two seem like a natural for comparisons.

I'm interested because I might be switching from my current fostex-based Cain & Cain IM-Bens(96dB) w/ C&C dual passive subwoofers(driven by IcePower 500ASP) to a set of massive 15" fullrange coax corner horns good that are 95dB 26Hz-11kHz(see graph below). And these things supposedly have startling bass response. I'd add a pod horn tweeter above 10k.

Anyway, I'm a tube addict and cannot see giving them up cold-turkey, but I need an amp with substantial current reserves and low frequency control for real dynamic passages. I know 200+wpc is overkill with ~96dB speakers(94dB@26Hz), but I want substantial overhead to keep the amp in it's most linear region and far out of it's rising distortion curve. Both the Moscode and Butler fit the bill.

[tvad4]

IMO, your best bet is to do a home audition of both, since how each functions in your system will be unique. The Moscode is available with a 33 1/3 day in-home trial. I don't know about the Butler.

[zybar]

I haven't heard both amps directly compared in the same system, but I own the Moscode 401HR and I have listened to the Butler amps on quite a few occasions.

The Moscode has better drive and dynamics (it drives my Salk HT3's easily and with authority) with a cleaner and less colored midrange.  The music flows out of the Moscode and produces a nice big image that is soooo easy to listen to.  There is tons of detail, but it really is about the overall enjoyment factor with the Moscode amp.

The Butler is a good amp at a good price (especially used), but I feel it doesn't match the Moscode in any particular area or in overall presentation.

I highly recommend you at least audition the Moscode and take advantage of their 33 1/2 day trial.

George

[brj]

darkmoebius, I can't help you answer your question, but the other amp that might be worth investigating is the Van Alstine Ultra 550.  I haven't read of any direct comprisons against the other two amps you mention, but it has received many positive reviews.  It is also a 250W hybrid amp.

(FWIW, I have heard the Moscode several times now, and have also been very impressed.)

I haven't heard both amps directly compared in the same system, but I own the Moscode 401HR and I have listened to the Butler amps on quite a few occasions.

Ok, George, that's the second time you've mentioned that you bought the Moscode in as many days... time to publish the BAT vs. Dodd vs. Moscode review!

[95bcwh]

He told AC members at the RMAF what he thought about the three amps.. you missed this year's RMAF.. you probably will have to wait until next year to get his thought

darkmoebius, I can't help you answer your question, but the other amp that might be worth investigating is the Van Alstine Ultra 550.  I haven't read of any direct comprisons against the other two amps you mention, but it has received many positive reviews.  It is also a 250W hybrid amp.

(FWIW, I have heard the Moscode several times now, and have also been very impressed.)

I haven't heard both amps directly compared in the same system, but I own the Moscode 401HR and I have listened to the Butler amps on quite a few occasions.

Ok, George, that's the second time you've mentioned that you bought the Moscode in as many days... time to publish the BAT vs. Dodd vs. Moscode review!

[JoshK]

Not trying to be a d**k but how does the Moscode resemble the original OTL? It has a SS output stage (not that that makes it non-OTL like).  Which OTL, futterman or circlotron?

[darkmoebius]

Not trying to be a d**k but how does the Moscode resemble the original OTL? It has a SS output stage (not that that makes it non-OTL like).  Which OTL, futterman or circlotron?

Two reasons:

1. George Kaye intentionally aimed for an OTL like sound as a result of his experience working  with the Jules Futterman design at New York Audio Labs(NYAL).

2. The amp is transformerless - the triode driver stage is dc-coupled to the speaker load through the output devices so they actively respond to the varying speaker load.

Now, I'm not saying that the Moscode qualifes as a traditional OTL amplifier (much like Berning's amps don't), but that it does share more similarities and goals with that design than the Butler.

To quote the Moscode website:

The challenge for me has always been delivering the tube refinement and sonics of the Futterman OTLs while using efficient solid-state output devices that can handle the heft and control in the bottom end. In a word, I have always wanted to combine the best of tubes with the best of solid state perfecting the union to bring about an unparalleled amplifier.

BK Butler's Tube Driver BLUE technology places the triodes exactly where they should be: DC coupled through the output power devices to the speakers. Therefore, the tubes are positioned to naturally and actively respond to the dynamic speaker load. This also completely eliminates one of the most inefficient and non-musical components in a typical tube power amplifier: the Output Transformer. Without the phase shift and induction generation caused by hundreds of turns of wire and massive core iron to overcome, BK Butler's newly patented current multiplying DC coupled circuitry allows the 6SL7GT output driver tubes to directly operate into the constant ratio-reduced speaker load. This novel design allows the tubes to safely produce authentic power vacuum tube dynamic characteristics hundreds of times greater than their original design capabilities.

IMO, your best bet is to do a home audition of both, since how each functions in your system will be unique.

If only that was financially possible.  I've still got to pay for the custom corner horns to be made along with the rare drivers. I also need to try an active preamp(or two) to compare with my S&B TVC and both amp(s). I could swing a used preamp and Butler, but not either with the Moscode.

"So much to do, so little money"

[RPM123]

"The music flows out of the Moscode and produces a nice big image that is soooo easy to listen to.  There is tons of detail, but it really is about the overall enjoyment factor with the Moscode amp."

I have not heard the Moscode, but the above quote mirrors some of the qualities that I find using the Butler 2250 in my system.


Butler 2250, Jeff Rowland Synergy IIi, Dali Helicon 400, Ayre C5xe, Reality speaker cables