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Rich; organic true balanced amp w good detail $6k

Suggestions welcomed & appreciated- here are the Criteria:

- fully balanced architecture
- rich, organic sound, extended bass, silky highs, but not at the expense of obscuring detail
- No OTL (too many tubes/heat)
- SS (Class A bias) or tubes OK
- 20-200 wpc ok, the lower the better though all things being equal- well built power supply crucial
- stereo amp easier to put on my Sistrum rack, but mono-bock architecture also considered if better performance
- $6k or less used would be ideal, but would consider up to $8k used if there are no world-beating contenders at the $5k-$6k used price point

Preamp is a modded Sonic Frontiers Line 3- extremely neutral, hence the desire for a richer-sounding amp to balance. High efficiency speakers from Coincident- large open concept room (main floor of house). Re: tubes, have used ARC VT-100 MKIII- good- airy w big soundstage, but meatier mids would be better. Also had Wyetech Topaz 20-watt SET, superb, if slightly lean in the mids (and not fully balanced, but shows you how powerful 20 watts can sound with a well-built power supply) For SS, am considering Pass XA.5 series (they now can run balanced from what I understand?); Clayton Audio M-200 (but unfortunately over the price-range).

Thanks in advance for any suggestions- I have an open mind, so bring it on!
sutts
Post removed 
nutella
223 posts
 
Three inputs on the Lamm.
Balanced
Pin assignment:
pin 1 = signal ground;
pin 2 = non-inverting input (+);
pin 3 = inverting input (-).

Non-inverting
Inverting
The amp must use a shorting plug on the inverting input if not using XLR input.


cytocycle
1,043 posts
 
The Lamm's are not a truely balanced design because Vlad doesn't believe it is necessary for consumer requirement as he can achieve the low noise with his single ended design. If you read his manuals, or an interview with him he will state this.

Drive and hear your friends Lamm's, and bring your preamp to make sure it can work with their high impendence.. You might end up with not enough volume increments because of the amp sensitivity. (I went through 3 preamps before finding one that worked correclyt.. Rowland Synergy IIi and my Theta Gen VIII worked fine)
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
Man I hate writing long replies and having the computer crap out on me...

Condensed version: Grant and Bill, I don't know whether it was a 350A or 350A Reference. It was a couple of years ago, and I only had it on loan for a month or so. Definitely stereo version though.

Sutts: Another brand to consider is Plinius, either SA-250 mk IV, SA-102 or SA-103. All are very musical will killer bass, and are pure Class A bias designs.

Cheers,
John
t_bone
1,182 posts
 
The amp is the end of the chain when it comes to differentially balanced or not, and if there is anything to the "SET" nature of your amps, it will not matter a great deal I expect. I am not a circuit specialist, but given the way that the circuit runs through the tube, I cannot imagine how the "fully balanced" will matter to a true SET - I imagine it will only matter if it is triode-ified push-pull, and even then, circuit implementation will matter far more than whether the amplifier circuit is fully differentially balanced or not (the next part of the chain is speakers, which will not care whether the amp was differentially balanced or not).

The VTL 450s (the old ones, at least) have a triode/tetrode switch on the back (do NOT switch while the amp is on - some speakers do not like it).
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