Synthesis Amplifiers: One of High End's Best Kept Secrets?

@waltersalas I just sent a response to your message with a link to the PDF file but it looks like Audiogon's system has zapped the link and are reviewing the message I sent. Let me know if it comes through. I don't want to post the link to the file publically as I'm not sure Luigi intended it for that.

Cheers

Rooze

I have the A100 biasing information if anyone needs it (send a pm).

 I haven’t needed to change tubes yet so I haven’t needed to rebias, but it seems straightforward enough if you’ve a decent multimeter.

Ditto on the positive comments regarding the A100. I don’t think I’ve owned a better sounding amp and I’ve owned a few in over 40 years. I would like to try their monoblocks at some point but I’m quite content with the A100. 

I notice a little bit of a hum very briefly when first powering up my A100, but it quickly goes away. I have not noticed any noise at all changing the volume.

In the year I have owned the Synthesis, I have come to love it more and more. It is just a stunning piece.

Side note, purchased a Chord Mscaler. Really adds a benefit to the A40 when using its internal DAC.

My Synthesis A40 still is running without issue except for a humming upon warm up. Also, I can get some audible noise when changing volumes. Is this normal? Deja VU did not seem concerned with it.

Have you received your new DAC yet?

I wonder how the Baltic 4.1 compares the internal Synthesis DAC?

Subscribed. My biggest concerns about Synthesis are the awkward biasing procedure,  and reliability. The dealer is many kilometers away.

I’m presently running conrad johnson tube pre and amp but I keep toying with the idea of an "endgame" (hah!) tube integrated that actually sounds like music- to me.

Thanks you fine folks for all the good info so far.

A question for the crowd.  I am looking for a DAC to replace a Bricasti DAC.  I had the pleasure of a home demo of the Synthesis Roma DC69 DAC, which I was told was even better than the onboard DAC in the Synthesis amps.  Has anyone else heard the Synthesis DAC other than the onboard version?  I would be interested in your listening experiences.

Thanks @woodsage.  If the A100 Titan is wired the same as your Synthesis gear then my suggestion was a waste of time.  Oh well, doesn't hurt to try being helpful.

Luigi is a great guy.  I got to spend the better part of the day with him and he is very engaging, interesting, and willing to help with issues that crop up.  The brand has cauth on in Asia, so they are very busy these days.

@woodsage Small world and coincidence indeed and thank you for the kind words. I figure when folks have Synthesis gear it's likely from Deja Vu. And glad Luigi helped you troubleshoot he souneds like a great guy from all I've heard.

@jond

I checked out your system, very nice and a bit of a coincidence here:

Both my amp and a Synthesis Roma 510 I bought at the same time (for a friend) came from Deja Vu Audio. They were sold as demos to a local in VA.

Both of them developed problems shortly after receiving them. My buddy’s amp stopped working on one side and mine developed a very loud hum.

With the help of Luigi at Synthesis both problems were diagnosed and remedied. My friend’s amp had a failed bridge rectifier and mine turned out to be (ironically enough) a bias problem.

Through this process I became very familiar with the construction of these amplifiers.

As to virtual systems, I guess I’m just too lazy. I’ve been into high end audio for forty years and a member of Audiogon for over 20 years and just never had enough interest to post my many systems over the years.

Good listening.

@woodsage Great info and would be curious to see your system consider posting on virtual systems page.

https://www.audiogon.com/systems

The 4 bias pots in my Roma 27 AC are very small pots soldered to the circuit board on either side of the chassis. To remove them safely from the circuit board the amp circuit board would have to be removed and the pots desoldered. Not sure how you would mount them so they are accessible from the outside. Additionally the 4 resistors where the bias is measured span the width of the chassis. So not easily accessible from the outside. Retrofitting external bias access is way more of a PITA than just flipping the amp over a couple times a year to check the bias at least IMO. 
 

Make sure you discharge caps before touching anything as the unit will probably have over 300V of stored current and verify with multimeter that it's safe to work on.

Wig

walter, yes, be very careful what you touch inside the amp.

Remove all the tubes before turning it over and removing the bottom cover.  Don't want any accident with those.

Take whatever photos as necessary of original wiring to be certain all correct after relocating the pot.

Depending on the layout, longer wires may be needed with the new pot position.  Try to use the same gauge and colors as original.

Verify from Synthesis what the bias reading should be.  Even with that longevity you may want to check it a couple of times a year.  Be sure amp is fully warmed up when reading (one problem with inside pot location).

Good luck and enjoy.

I have a Synthesis Roma 27 AC and love it. It was very easy to bias with a little instruction from Luigi. Yes, it has to be done inside the amp and an outside bias adjustment would be easier. As far as lethal voltages; sure, you have to be aware and have some basic knowledge. Much like you do when driving on the freeway at lethal speeds surrounded by drivers scrolling through their social media posts.

@pryso 

Now there's a thought! I am going to look into that possibility right away. Thanks for a creative potential solution. This is my only issue with this amp, which continues to delight me every day.

Walter/Chris, and others, re: biasing problem.

Years ago I got a pair of Cary 100w mono amps.  I enjoyed the sonic match with my speakers at that time but was frustrated that the bias pots were installed inside the amp chassis.  Needless to say a real pain for adjusting bias.

I'm not knowledgable about electronics but could see no reason why the bias pot could not be installed on top of the chassis.  So I carefully drilled a hole in a convenient place on the top and mounted the pot there.  It was a simple process and made adjustments so much easier and less time consuming.

Since I'm not familiar with Synthesis amps I have no idea if this could easily be done with them, but I certainly would investigate. 

Yes, the Roma 69DC is a very good DAC.  Also good are the DACs built into Synthesis integrated amps.  This is a company that delivers good value. 

Italy does have quite a few good Audio companies.  I like the stuff from Lector; they make very good DACs and phono stages.  I recently discovered some pretty decent sounding speakers from a company called Rosso Fiorentino.

Has anyone heard the Synthesis Roma 69DC DAC?

I recently heard one and felt it was as good or not better than my current DAC which costs twice as much.

Seems too good to be true,

There is a lot of really wonderful audio equipment coming out of Italy and the former Eastern Block Countries. Enjoy your acquisitions Walter.  

Thank you and congratulations on your soon to arrive new DAC.

@azwill 

My cable evaluation is on hold until the arrival of my new DAC, the Lampizator Baltic 4.I expect it to arrive in the next week or so, and then we'll see how it shakes out. I will also be comparing a couple of very nice AES/EBU cables--an Infigo prototype and a Shunyata Sigma V2. 

I will report back when I have some solid impressions. Thanks for your interest.

@waltersalas,

I may have missed it, but saw in this thread you were evaluating USB cables.  Did you come to a decision on the Muon USB?  I would be interested in your USB evaluation conclusions.  

Thanks in advance

Hi all!

I agree with you about the Synthesis gear. I bought a combination: an older Synthesis Harmony, two Sythesis The Theatre monoblocks and the Synthesis CD player. I liked the way it looked.

When I got home and attached it for fun in the dining room to an old set of Rogers Studio 1 loudspeakers I was a stunned at how good it sounded! I used a simple, but very good Topping D70S DAC. So my experience with Synthesis is indeed a good one! I am now in the process to find the best set of matched tubes to place in these pre/power combo. I do the matching of the tubes on a calibrated AVO MKIII tube tester and the biasing should not be a big problem.

What I wanted to let you know: I own quite a lot of gear and I like to try a lot. My tip: try to find a USB bridge for your "older" DAC. ;o) 

What I am using for a long time is a VTL Reference DAC. You know maybe... the one with the two Ultra Analog DAC's in there and with tubes form 1990. I purchased a USB bridge X-SPDIF 2 from Matrix Audio to cleanup the USB signal and this changed my whole DAC/streaming experience. It merges the old world with the new world. 

I am now streaming from a specially powered HPE SFF Z240 workstation (NVMe based) through the Matrix Audio X-SPDIF 2 to the VTL Reference DAC.

Maybe you have tried allready, but you might try a X-SPDIF 2 in front of your Lampizator?

Well, before I jump off the A-70 bandwagon, I just upgraded to the Audio Note Lexus cable and it made a huge difference in the solid state amp from the previous AN cable. The AN-LA cable sounded fine with the synthesis, but did not sound good with the Accuphase. Now, I can say both amps are equal in its value to the overall system. 

When I have time later in the week, I'll call about the remote.

Believe me, I know what you mean about going to back to solid state. I had some very nice, very highly regarded solid state amps through here the past couple of years, but I much prefer the Synthesis A100 to any of them. It is very hard to turn it out and go to bed at night, always a good sign!

I just cannot seem to go back to my Accuphase A-70 after the purchase of the A40. I just enjoy listening to it. Is it because it is the new toy, perhaps. It is just more listenable than the solid state amp

I genuinely believe that with audio/music , just trust your ears. Whichever component you gravitate toward naturally is the right choice for you.

Charles

To be honest, I do not know. I have yet to use the remote. He just mentioned it. 

I just cannot seem to go back to my Accuphase A-70 after the purchase of the A40. I just enjoy listening to it. Is it because it is the new toy, perhaps. It is just more listenable than the solid state amp. 

I have not heard this.

Hmm, what kind of problems? The only thing I have noticed with mine is that it can be a little bit balky and the volume control is not as smooth as I would wish. It doesn't really bother me that much, but an upgrade would be welcome.

I believe my Lampizator Baltic 3 has a slightly bigger and slightly more layered soundstage, but otherwise they sound more alike than different.

As stated above, I am now an owner of the A40 for about week or so. I am currently listening to the onboard DAC via USB cable from my streamer. Yes, it sounds great with a warm sound signature. In contrast, when I listen to the A40 with my Accuphase D-37 DAC the sound is great as well, but slightly more analytical. 

On another note, Vu stated they are having problems with the new remotes. I have yet to use mine. He states they may be recalled. Have you heard this as well?

@waltersalas 

Maybe other Synthesis owners are experiencing a bigger gap in performance than I seem to be between their external DAC and Synthesis' own built in DAC, but when Larry says it's formidable, that's no joke

The LampiZator Baltic 3/4 DAC  is highly regarded. Quite a compliment to acknowledge that the built-in Synthesis DAC is toe to toe competitive.  I believe that in audio one “generally “ gets what is paid for. However, I’d be the first to admit it’s hardly linear. There are undeniable exceptions and diminishing returns is a very real circumstance.

With high end audio you can certainly find on occasion, equal or more for less cost. so I can’t say that I am surprised by this scenario.

Charles

I'll be interested in this comparison as well. I continue to marvel at my A100 every day. I'm glad Larry mentioned the onboard DAC again. I have been driving myself crazy for a month comparing it to my Lampizator Baltic 3, which is a terrific DAC that suits my tastes nearly perfectly, and I sometimes think it is enough of an improvement that I'll keep it or even upgrade the Baltic 4.

But the A100 DAC sounds so good to me that it really does force me to consider the law of diminishing returns. I've been comparing for a month and the differences are by no means night and day. You throw in the cost of a decent pair of interconnects and an extra power cord, and pretty soon you're closing in on $10k for what, maybe a 5-10 percent improvement? The fact that this is even a horse race speaks volumes.

Maybe other Synthesis owners are experiencing a bigger gap in performance than I seem to be between their external DAC and Synthesis' own built in DAC, but when Larry says it's formidable, that's no joke. I've had several very highly regarded integrated amps with built-in DACs, and not one of them impressed me the way this one has.

I like the Soro amp a lot, likewise the AN Oto.  The comparison should be interesting.  I've heard various AN speakers with the A100 and A40, and these amps play very well with AN speakers.  Both Synthesis amps will be loafing a bit playing any AN speaker.  Don't forget that the Synthesis has a pretty formidable built in DAC.

@next8 

Just for fun, I’m going to demo the AN Soro se signature tomorrow largely because I want to hear how it sounds with AN speakers. I’m sure it will be great but how will it compare to the A100T? We shall see.

This could be a very compelling comparison.

I’ve had my A100T for about 6 months and love it. Powering Audio Note AN/E Lexus HE Signature speakers which I bought at the same place brings exception listening experience. My favorite part is actually the no sound, the air between a singers’ breadth. All of this system was recommended after my dealer, demo’s at my request, Conrad Johnson mono blocks. The A100T killed it. My dealer also recommended a streamer they use to demo various equipment mostly speakers. The Sonos Port. Around $500.  And it sounds amazing too. 
 

Just for fun, I’m going to demo the AN Soro se signature tomorrow largely because I want to hear how it sounds with AN speakers. I’m sure it will be great but how will it compare to the A100T?  We shall see. 

I purchased the Synthesis A40 to power my Dali Epicon 2 monitors. When I got home I connected the A40 to my primary system consisting of Franco Serblin Ktemas. Needless to say, the amp never left the primary system and now powers my Ktemas. Plenty of power.

I mainly listen to vinyl through it, but when I compared the internal DAC to the Accuphase DC-37, well I prefer the Accuphase. With this said, if needed, I would be happy with the A40 DAC. I also purchased Audio Note speaker cables to go with it. Good combo. 

I listen to my Accuphase setup mostly, but for listening sessions with the right music I switch on the Synthesis. I am happy with the purchase. Glad to hear others are well. Sounds like we purchased from same dealer in NOVA

I will never go back to SS. Maybe a hybrid. 

Awesome looking tube Integrated amp and the changes grannyring mentioned would be a worthy upgrade. I have owned manually biased tube amps and they all drift after 30-45 days of use as the tube ages requiring regular biasing to maximize tube longevity.

Wig👍

I get it for sure, Bill. This "quirky" design flaw could well be a non-starter for many, and I certainly wish they'd make exactly the adjustment to their amps you have suggested.

I will send this advice along directly to Synthesis, for whatever good that might do. All I can say to anyone out there is don't audition it unless you're willing to live with it :)

Agreed.  I would also own the same amp. No issue for me. I am sharing something folks living around the fruited plan should think about.  Also hoping the company or dealers read this so future product has probe locations on top of the amp. 

It is highly unlikely I will do this myself. Then again, the tech for Deja Vu told me that the KT66 tubes in the Synthesis last an average of six years. I'm not exactly fretting over it. I have a tech twenty minutes up the road who could do it, or I might send it to Virginia to have them do it when the time comes for tube replacement.

For context, I just sold an amp that retails for more than twice as much as the A100. If I also end up selling the DAC, interconnects, and digital cable as seems very likely given the quality of the onboard DAC in the unit, I will be pulling about $10K out of the system and still have sound I much (much!) prefer. For me at least, that's worth the nuisance of having someone else setting the bias on the output tubes when the time comes for that. Your mileage, as they say, may vary.

Yes, the Synthesis rep mentioned in his email the need to be careful about the voltage exposure.

Yes, the problem is under that bottom cover you have some 400-500vdc at your fingertips and one better know what the heck they are doing. A wrong move and serious injury or death is possible. So this amp is really not bias capable by most folks.

If the internal bias points are well away from high voltage and “safe” then ignore my comments. Not sure this is the case however.

l strongly suggest the amp maker simply provide bias slots on top of the chassis where one can plug in their multimeter. This is simple to do, not costly, and so needed.

Wonderful amp for sure, but this bias issue is a real one. Not my intent to be negative or hyperbolic here, but simply sharing the realities. Hard to find techs in most places nowadays making it a hassle to bias when needed. I have to think this could be addressed and rather easily.  

Given clear instructions, I don't think it is hard for anyone to bias their amp themselves.  But, the problem is that it is hard to gage how experienced is the person attempting this, how much experience they have with a multimeter, and there is always a concern that someone might poke a probe where it should not go.  I can understand the reluctance to encouraging people to do this on their own.

I was at a pet store once where the owner got a call from a customer who just bought an air pump and could not get it to work.  The customer lived nearby and brought it back to the store a few minutes later.  When she took it out of the plastic bag, water was leaking from the pump.  The dealer asked about how she used it.  She said she plugged it in and just threw it into the tank.  I bet that was not anticipated.

Per my email correspondence with Synthesis :

-  "amps are manual bias except the ROMA96DC and ROMA96DC+ that have autobias"

- T"he biasing procedure is internal and need to open the amp for setting"

- "The bias setting needs to be done when the tubes are spent, or when put the     new. ... need a multi meter for to read the bias value (current) and a little knowledge of electronics."

  - "if you need a bias setting manual, I’ll send you"

I've emailed Synthesis directly about the biasing to see if I can get specifics on the process; will post back when I get a response.

Not yet, but I am sure they will. The tech told me that he actually made a video of the process for one owner, but when he watched it, he decided to bring the amp into the shop after all. Nope, not ideal, but I won't be selling mine, that's for sure.

Thanks for the update. Not ideal. Did the dealer tech provide you with the schematics/process outline for when the time comes to taking it to a local tech?