[trackball02]

Anyone critically  listen to these two amps in the same system? Both seem to be great products and reviewed favorably. Is there any particular music that sounds better with either amp?

I'm going to upgrade my solid state amp (gainclone). I currently have the Avastar pre and Ultravalve amp with Zu Superflys and looking to purchase this Spring before the heat of the Summer to swap out my Ultravalve. I assume that both amps do not generate much heat. I not too concerned about the cost differential, just want to get the best sounding amp.  Thanks.

[kc8apf]

I own a Synergy 240/3 and FetValve 400R.  A few weeks ago, I tried swapping between them to see what differences I could find.  The rest of my system is an Oppo BDP-83 via HDMI and a Technics 1200 to a Denon 4310CI used as a preamp.  Speakers are Salk Supercharged SongTowers.  The 4310 has Audyssey turned off and is put in Direct mode.  I realize my frontend is probably the limiting factory and that something I'm planning to rectify this year.

I could hear very little difference between the amps but ultimately find the 400R a little cleaner on bass.  This was most pronounced with particularly dense music, such as Sleigh Bell's Tell 'Em, where large bass hits tend to suck the vocals out of the song on lesser amps/speakers.  The Synergy 240/3 is a very good amp and holds up well against the 400R.  Since you're not concerned about price, go for the 400R and know it was well spent.  For those that do have a price constraint, the Synergy series offers a very compelling and cost conscious alternative.

[trackball02]

kc8apf, Thanks for your experience and comments. Are you running the stock tubes in your 400R?  How warm do you amps run?

[kc8apf]

Stock tubes in the 400R.  Neither gets particularly warm.  I'm listening to the Synergy right now and it is barely warmer than room temp.  I remember the 400R being a little warmer but not much.

[trackball02]

Great info. Doesn't seem like I can go wrong getting either of the two amps. I'm leaning towards the 400R.

[kc8apf]

Mine is up for sale: http://www.audiocircle.com/index.php?topic=111867.msg1158423#msg1158423

[trackball02]

Oh, I did not know, why are you selling?

[kc8apf]

I run a 3.0 setup so I really only need the 240/3 to run everything.  I bought a new set of speakers so I need to sell off some extra gear to recoup from that.  I really like the 400R but can't justify running the 240/3 for a single channel.

[I.Greyhound Fan]

Anyone critically  listen to these two amps in the same system? Both seem to be great products and reviewed favorably. Is there any particular music that sounds better with either amp?

I'm going to upgrade my solid state amp (gainclone). I currently have the Avastar pre and Ultravalve amp with Zu Superflys and looking to purchase this Spring before the heat of the Summer to swap out my Ultravalve. I assume that both amps do not generate much heat. I not too concerned about the cost differential, just want to get the best sounding amp.  Thanks.

I got to listen to a 600R and a Synergy amp at Mr Van Alstine's house last year.    I found both amps to be excellent but with different flavors.  I like both amps and would have no problem owning either one. The R series has more detail, a wider and more transparent sound. I am very impressed at the space between instruments that the R series amps produce. Bass is very tight and extremely well controlled.  They are a fantastic amp.  I found them neutral to just a hair on the sunny side.  The Synergy amp is slightly warmer and not as transparent.  It definitely has some tube like qualities. Bass is excellent and well controlled.  I think the Synergy amps will be a little more forgiving of poorly recorded music. Both are excellent amps, I guess it depends on what you are looking for and how much you want to spend.  My final thoughts are that the R series is a step up in sound and compares well with amps in the $4-5K range.  PM me if you have further questions.  (by the way, I did get to take a 600R home and did a review on it in the past.  I have an Ultra II preamp with all the mods as well as a modded Ultra II DAC both units running vintage 1950s Raytheon and Sylvania 6CG7 black plate tubes, Parasound A21 amp that I would like to upgrade and Magnepan 1.6's)

[trackball02]

I. Greyhound,  I purchased kc8apf's 400R and just got it today (it needed a good home  ). What a great sounding amp! Very impressed and a keeper. Your comments about the FET Valve are spot on. I can't see ever spending more for an amp. I'm glad I got it. I appreciate the engineering that went into this amplifier.

It is going to be hard for me to decide what's better: my current Ultravalve or the new 400R. Since, the 400R runs a lot cooler, I'm really going to like the 400R during the Summer months.

[JonnyFive]

I spoke with Frank about the two amps paired with the Salk Soundscape 8's.  He said he prefers the FetValve 400R for the SS8, but I have a question/problem...

I was planning on hooking it up to a Panamax strip with the 12v dc trigger.   Heaven forbid I have to get up from my couch to turn my equipment on.   Frank mentioned that there is a part in the FetValve...a resistor?...that when cold protects against inrush current.  When warm it does not.  So turning the amp off then back on right away is a big no-no. 

However, my Airplay on the receiver locks up from time to time and everything has to be restarted.  The gf will power it off and back on without even thinking.  So I don't see how to make the FetValve work in that situation?  Is there a 12v dc trigger with a timer?? Lol

I'd prefer to go with the FetValve but I can't see how to make it work in this context.

Jon

[avahifi]

The part is an Inrush Current Limiter.  I would like to have at least one minute between turn off and hot turn on of a Fet Valve amplifier.  Without this short wait, you may blow the main 15 amp slow blow fuse at hot turn on once in a while.  The fuse is user accessible on the back panel of the amplifier so it is no big deal to change it.  Just keep a few spares on hand. 

Of course the S450 is an awesome amplifier too, and being solid state, does not have this issue.  It just plays instantly, from either cold or hot turn on.  With our newest specification power transformers, it makes more power than ever.

Frank

[JonnyFive]

The part is an Inrush Current Limiter.  I would like to have at least one minute between turn off and hot turn on of a Fet Valve amplifier.  Without this short wait, you may blow the main 15 amp slow blow fuse at hot turn on once in a while.  The fuse is user accessible on the back panel of the amplifier so it is no big deal to change it.  Just keep a few spares on hand. 

Of course the S450 is an awesome amplifier too, and being solid state, does not have this issue.  It just plays instantly, from either cold or hot turn on.  With our newest specification power transformers, it makes more power than ever.

Frank

Keeping a supply of fuses could be an option.    Everything I've read on the forums seems to indicate that the FetValve is going to be a better match with the SS8s.  I'd really like to make it work, if possible.  I'll keep thinking on it.