[SoundSound]

Dear Audiophiles! 

I am looking for a power amplifier with balanced circuit topology to replace Acurus in my modest Hi-Fi setup:
 
Mac mini (USB3 output) -> Singxer SU-1 ->
Yggdrasil DAC (AES/EBU XLR input) ->
Primare PRE30 preamplifier (AES/EBU XLR input) ->
Acurus A250 power amplifier (RCA input) ->
Monitor Audio RS-6
 
Any info/advice is very much appreciated. Please chime in! 

P.S. I am considering Lindell AMPX power amplifier, but not sure if it is a true balanced/differential design…

[TomS]

Very few are actually differential input to output, with balanced connections. As I understand it these are:

AVA DVA700
http://www.audiocircle.com/index.php?topic=149749.0

[JLM]

Off the top of my head:

Channel Island Audio amps (prices/wattages vary, if ordered with XLR outputs)
Class D Audio SDS amps (about $600, various wattages)
Schiit Vidar ($700 USD, stereo 100 watts, not yet released)
Temple Audio mono-blocks ($660 USD, 70 watts, if ordered with XLR output)

[borism]

SoundSound, you have not posted your budget for a balanced amplifier.

I used to have a BAT VK250 which was very nice and balanced. However, not knowing your budget a new one might be to expensive.

[Speedskater]

A fully balanced amplifier circuit:
1] adds to the design challenges.
2] adds to the cost.

[Randy]

Son of Ampzilla II = "Fully balanced input-to-output with full four-quadrant differential push-pull feedback from both sides of the speaker."
I have one of these and just love it. Using it with the Tortuga LDR balanced version pre with the balanced tube buffer. Magic.


http://www.sst.audio/son-of-ampzilla/

[twitch54]

three letters ........... B A T !!

http://balanced.com

[brj]

Pass Labs are also fully differential end-to-end.  The 0.5 series are a bit warmer in the mids, the 0.8 series a bit more linear and with a bit lower noise floor.  The XA versions are more heavily biased into Class A operation, if your speakers are sensitive enough not to need extreme amounts of power and you are comfortable with the somewhat less efficient operation.  (And it does looks like your speakers are a bit more sensitive than is typical.)

[SoundSound]

Thank you, thank you all very much indeed, dear “brothers-in-sound”! 

True, I did not specify any price range in hope I would get from your responses some ideas what you feel to be a reasonable expense for my setup… 

I was budgeting for up to 3K new, but I see at least two excellent variants for around 3.5K (DVA700 and Son of Ampzilla II), and a few even more expensive stellar offerings from Pass Labs (XA30.8; XA30.5 - discontinued, unfortunately) and BAT (VK-225SE !!!).

Let us draw the line at 3.5K and go from here! 

By the way, are there any widely accepted budgeting guidelines for building source - amplification - speakers Hi-Fi setups? Something like 30% - 30% - 40% ? 

I was looking into class D amplifiers and saw, what I consider to be a serious limitation, that even the best of them have Frequency Response up to 35 - 50 KHz only… 

Schiit Vidar (very friendly priced at $700 per box): what do we know about it? Could you please explain what “dual mono to the transformer design” means? “Buy two and connect them with balanced XLRs to a pre-amplifier for a pair of monos that’ll drive 400 wpc into 8 Ohms.” - sounds very good indeed! We need to wait a bit for them…

I must confess, I have never heard any of the AVA amps (in my neck of the woods way up North we have a very limited supply of quality components). Could you please help me to find the full specs of DVA700? Is it a hybrid tube/transistor design? I see nothing published on the website, unfortunately enough, and am wondering why this is the case… Have they anything to hide?! 

And last, but not least, Son of Ampzilla II, 2017 TAS Editors' Choice Award winner! Excellent recommendation, Randy! Are you driving a pair of Roman Audio Centurion Loudspeakers with it? If my memory serves me well, they are quite sensitive at 93 dB… Do you believe it would be a good match for my basic Monitor Audio RS-6? I have a feeling my next upgrade should be the Loudspeakers… 

Thank you very kindly, my dear friends! I appreciate your help very much indeed, believe me. In my situation, I will have to make my final decision based largely on your recommendations. 

[Randy]

I still have the Roman Audio speakers, but they have been replaced by amphion 3LS, a very nice speaker made in Finland. In regard to the Son of Ampzilla II and your Monitor speakers, I am not familiar with them and can't say how they would work together, but an excellent amp should work well with any speakers, I'd guess, assuming they have enough power. The SOA lit up the Roman audio pair like technicolor before I had the amphions, and are doing the same with them.
 I will send you a P.M. concerning AVA. (all good.)

Randy

[mca]

I believe the Modwright  amps are fully balanced and sound great as well.

[I.Greyhound Fan]

Take a look at my review of the DVA 700 in the AVA circle that I just posted.  It is a great amp for the price.  You can also find a used Pass X250 for about $3000.  Both are fully balanced.  A Parasound A21 is also balanced.  I own both the Pass and A21.

[charmerci]

I must confess, I have never heard any of the AVA amps (in my neck of the woods way up North we have a very limited supply of quality components). Could you please help me to find the full specs of DVA700? Is it a hybrid tube/transistor design? I see nothing published on the website, unfortunately enough, and am wondering why this is the case… Have they anything to hide?! 

I've been dealing with Frank since the late '80's. Sensible no-nonsense guy. He often doesn't publish standard specs because he says they often don't look in the right direction. I've never bought his super-expensive stuff but his least costly stuff is really good. You'd have to spend a LOT more to get better sound.

[I.Greyhound Fan]

SoundSound, the DVA 700 is all Solid State.  The DVA 850 mono blocks are hybrids.  The 850's sound awesome.

If you want to know spec's, give Frank a call.  His customer service is second to none.  His gear is built to last. However, if you are looking for audio jewelry, you should look else where.  There are no fancy chassis or lights. 

I preferred my old Pass X250 to the DVA 700 even though the 700 did some things better but that does not keep me from recommending the 700.  At $3700, it is hard to beat, plus is has a 30 day money back guaranty.

[brj]

I was budgeting for up to 3K new, but I see at least two excellent variants for around 3.5K (DVA700 and Son of Ampzilla II), and a few even more expensive stellar offerings from Pass Labs (XA30.8; XA30.5 - discontinued, unfortunately) and BAT (VK-225SE !!!).

Note that the Pass XA30.5 routinely sells used for under $3k.  There was one listed on Agon yesterday for $2.8k, and I've seen $2.5k in the past.  If you were set on new because of warranty concerns, be aware that Pass Labs service is fantastic.  While they only advertise 3 year warranties, I've never actually heard of anyone that wasn't able to have their amp serviced regardless of age.  (My amps were purchased used, and I had one of the face-plates replaced outside of the 3 year mark.)

Having said that, you should audition whatever strikes your fancy and go from there.  All of the proffered recommendations in this thread are worth considering, but suggestions and reviews can only take you so far!

(I should acknowledge that my system evolved into a fully differential end-to-end configuration because I pursued two pieces of gear that many feel sound best on the differential inputs/outputs - my Pass amps and Auralic Vega DAC.  I didn't otherwise have an identified reason - long cable runs, strong EMI/RFI, etc. - to prefer a differential vs. single-ended system design.  I do happen to appreciate the mechanical interface afforded by XLR connectors, however.)

[jtwrace]

If you were set on new because of warranty concerns, be aware that Pass Labs service is fantastic. 

I will second that.  My dad had the LCD screen go bad on his Threshold T3.  I called Pass and he actually told me which current replacement to use as it's the same as what they use now.  Now that's service considering the T3 is from ~1994

[I.Greyhound Fan]

Yes, Pass has great customer service.  They are always willing to help when you call.  I have had no issues with my X250 amp.  But it will give you a double hernia if you try and move it around by yourself.

[SoundSound]

Thank you, thank you all very much! 

In my mind, the power amp is a backbone of the system, and the process of selecting one should be exhaustive.
I would definitely prefer to go with a brand new box (this unbelievable smell of a brand new piece of electronics…), and warranty is certainly very important as well, especially for us, Canucks…
So far I see two contenders: DVA700 and SoA II. Do you believe Schiit Vidar should also be considered, please? Are they even in the same league, I wonder? 

Please chime in! 

[I.Greyhound Fan]

Other amps you may want to consider are the AVA 400R and 600R Hybrid amps.  They can be built with XLR.  It will not be truly balanced however.  The Van Alstine R series amps are great. I prefer them over the DVA 700.  They have totally different sounds and you can tube roll to tailor the sound.  The 700 is darker and warmer sounding which I prefer but the R series are more musical with better bass, detail and they are more holographic.  The R series and 700 are both great amps, just different flavors.

[SoundSound]

No wonder you like them: AVA FET Valve 600R is the 2016 TAS Editors' Choice Award winner! 

Has anybody had a chance to listen to Schiit Vidar at AXPONA? Impressions?