Tube Amp (a 4 letter word): Unison Research S6 vs Belcanto C7R

[Stubies]

I just listened to a Unison Research S6 tube integrated amplifier compared to a BelCanto C7R - both through a pair of Spendor SP3/1Rs.
http://en.unisonresearch.com/2815/s6-new/
http://www.belcantodesign.com/Belcanto_C7R_DAC_Integrated_Amplifier.html

This exercise was particularly focused on one aspect: listening fatigue


The tube amp came out on top, a clear winner. It was smoother, deeper, and grippier - and all without listening fatigue, which i seem sensative too (perhaps more so with age).

The Belcanto was great as well, just not as good. And i definately found the piano/horn edges a bit too sharp or dissonant for me.

I also listened to the small Unison Research tube amp "Simply Italy", it was also great, though missed a bit of drive and punch.

I know this is a very simple observation/comparison - still it was illuminating for me, so i thought i would share

Also interestingly, Arif, the owner of Audio Lounge (london), also suffers from listening fatigue. He reported in his case it is caused by age and some hearing damage, usually accompanied by tinnitus (ringing in the ears). He says he can only listen to tube amps for extended periods.

Anyone else have a similar experience?

What is a good starter tube amp? I would like to research this more.

[brian2957]

Have a look at the dared tube amps Stuart . I had an I30 and thought it was very good . Scott Nangle who posts on here ( daytona600 )stocks them .http://www.scottnangle.co.uk/dared_12.html

[newton]

2nd hand s6 should only fetch £600 or so ,would have thought good starter with right speakers

[Stubies]

brian

thanks for the tip!, ive emailed them to ask prices

have you purchased from them before?

Have a look at the dared tube amps Stuart . I had an I30 and thought it was very good . Scott Nangle who posts on here ( daytona600 )stocks them .http://www.scottnangle.co.uk/dared_12.html

[brian2957]

Yes , I bought the I30 from Scott . Good price and service. The dared amps are also rated at 230v so are suitable for use in the UK .

[Stubies]

Graham,

that would be great! any idea where i might find one? Are they usually on ebay or somewhere else?

Stu

2nd hand s6 should only fetch £600 or so ,would have thought good starter with right speakers

[Virkon]

One on at the moment but it's past £600 with 5 days left.

[Stubies]

well - i went back to the same dealer, after having recieved a call that the setup was wrong and i should have another listen.

So i went back, and they explained that the BelCanto cd player had been set to 60% output, thus the Unison amps were being under fed.

So we listened again, and surprisingly both the S6 and the Simply Italy (smaller version) were great - in fact the Simply Italy was all you need (and 1/2 price).

Also, we listened to a pair of Spendor D7s - and i have to say the tweaters were even sweeter than the SP3s. The D7s sounded amazing - thought at 3k per pair they are 2x the SP3s.

I have a defined threshold for my next system: the 'goose bump' test. If you get goose bumps, it passes.

The combination Simply Italy and D7s pasted. They were that good! And no listening fatigue.

Thought you might like to know.

[Reffc]

A well designed SS amp shouldn't be giving you listening fatigue at all. Perhaps you need to listen to a few more before you jump into the tube amp waters? I'd be very careful too of making your mind up of one audition, especially if it wasn't in your own system.

U/R amps are OK. I've listened to a few and liked the Unico which represented great value for money too. However, none of their older "S" range could hold a candle to a multitude of other similarly priced valve amps. They all sound rather mushy in the lower registers to me and over-blown in the mids. The newer range are much much better and some like the new S6 (at last!!!) offer variable negative feedback to accommodate different speaker loads which is not only a welcome design addition but a necessary one and one which has transformed their performance. A little pricey though when comparing to the competition but a nice amp.

I'd throw into the suggestions for a valve amp some good used designs which should work very well with the Spendors. Have a look at a sorted Audio innovations 500, Leak TL12's, Stereo 20 or a used (serviced) Radford STA15. I deal with Jolida
myself being so impressed after listening to a few in my own system and would wholeheartedly recommend them, particularly the new JD302 and 801 amps which are stunning performers.

If you want to try an inexpensive Chinese built amp then there are just a few (quite literally) which are easy to move on if you decide against them and sound reasonable. The Yaquin MC-100B, Puresound A30 and Consonance Cyber 10S are all a decent listen. I can't really recommend anything else from the orient. Best sticking to European/USA built amps if you want quality.

[Audioman]

Listener fatigue should not be related to solid state. I'm sure there are examples of both solid state and tube that may contribute but a well designed example of either should not be fatiguing without being too 'pipe and slippers' and thus smearing detail. Using Cd as a source certainly imparts listener fatigue especially many older or budget designs. That's one of several reasons why I stick to vinyl LP as my main source. The same is likely with a file based audio using less than optimum source and/or poor quality DAC. I call it digititus. It's true that the warm and cuddly version of valve sound can reduce the problem. I suspect this was one of the initial reasons behind the valve resurgence in the 90s.

[Sovereign]

I have been a SS amp man for some time, I recently tried some very good and highly rated tube amps which were just excellent. I then put my NVA A80 monoblocks back in which were better by some way which is where I have settled.
NVA amps are free of listening fatigue, which is also one of my 'issms' as well.

[Sovereign]

If you want to try an inexpensive Chinese built amp then there are just a few (quite literally) which are easy to move on if you decide against them and sound reasonable. The Yaquin MC-100B, Puresound A30 and Consonance Cyber 10S are all a decent listen. I can't really recommend anything else from the orient. Best sticking to European/USA built amps if you want quality.[/QUOTE]
Yes I had a Yaqin 100b and it was very full bodied, detailed with plenty of grunt.

[Stubies]

Guys, thanks for the great recommendations and comments!

This topic "getting back the goosebumps" is rather important for me, and im excited to be close...

I will wait on the tubes, until i can hear the soon-to-arrive Exposure XV, paired with the new old Ushers and also the Epos ES14s - after that i will see what is next :)

will let you know the results!

[Stubies]

Paul (RFC) and Paul (audioman),

I dont know enough to suggest that SS is a partial cause of listener fatigue - just sharing observations.

And yes, CD source is definately a suspect, though the above test both used a BelCanto CD as a source.

Here is a question. Could part of the 'listener fatigue' issue be the 'Class' of the amplifier?

So for example my NAD C340 is a Class C (or so i read somewhere - but i cant seem to verify that just now). Your (RFC's) mono blocks are Class A and tube amps are generally Class A - could that be an indicator?

Yesterday's Experiment

At one of the HiFi shops i visited in london yesterday, i listened to a Krell S 300i integrated amp paired with electrostatic Marin Logan speakers (both about 2,600 gbp each). (yes there was a CD source here too, but dont stop reading yet)
http://www.stereophile.com/images/912martin.2.jpg
http://www.krellonline.com/assets/integrated/s300i.jpg

At first the 'listening fatigue' was present, though not overwhelming. In discussion with Robert the assistant, we tried another Krell, with no result.

Then... (drumroll) we switched the interconnects from RCA jack style to Balanced Line style - and guess what? the listening fatigue decreased significantly! both were excellent interconnects (a brand called Transparent - about 400 GBP each (ouch!)).

It was not completely gone, but reduced a lot. The end combination was great - not quite in the 'goosebump' league.

Thought i would share.
:)

[The Outcast]

Great amp.

[Reffc]

The class of amp is less important than the way it has been implemented, but yes, I prefer class A providing that some feedback is used. I no longer use Class A monoblocks, I use an EAR 869 integrated as a power amp and drive that with a Croft preamp. Interconnects shouldn't make a difference to listener fatigue unless they're doing something very wrong indeed (or very poor interconnects) but the differences you heard are likely more to do with balanced circuit V's single ended for that particular amp. It may be that most of the thought and care went into the balanced circuit. Also, output might typically be 6dB up on the balanced side so perceived detail and bass for similar volume settings would be more. A proper A/B comparison would need to be level matched before conclusions could be drawn. Nothing wrong with Class A/B/C amps at all but I draw the line at Class D. I haven't listened to one I've liked yet.

[Tarzan]

Listener fatigue should not be related to solid state. I'm sure there are examples of both solid state and tube that may contribute but a well designed example of either should not be fatiguing without being too 'pipe and slippers' and thus smearing detail. Using Cd as a source certainly imparts listener fatigue especially many older or budget designs. That's one of several reasons why I stick to vinyl LP as my main source. The same is likely with a file based audio using less than optimum source and/or poor quality DAC. I call it digititus. It's true that the warm and cuddly version of valve sound can reduce the problem. I suspect this was one of the initial reasons behind the valve resurgence in the 90s.


Spot on, l have had valve amps here that have given me listener fatigue, and also SS to address the balance a little.