Best integrated amps for Monitor Audio silver RS6

RDavidson · « **Reply #40 on:** 7 Feb 2013, 02:58 am »

I suggest getting these answers from VAS.
Check for bias drift after a few days.
I have no idea who makes the stock Cayin tubes. Probably the same manufacturer of Shuguang tubes, but that's just a guess.
Are you running it in Ultra Linear mode or Triode mode. I think my A50T would always default to Triode mode, which was a minor annoyance, because I found Ultra Linear mode to sound overall better in about every aspect.

Ericus Rex · « **Reply #41 on:** 7 Feb 2013, 01:06 pm »

Quote from: kinku on 7 Feb 2013, 02:05 am

Thank you. I tried hooking up to 4 there is some change, for better. Still will not say a significant change. The sound has more balanced out now. How much change in bias voltage you will consider as a sign of impending doom?
Mine was holding constant for few hour interval when I checked today. Do not know what make Cayin tubes are . Any idea?

Go to tubedepot.com and look over their selection of KT88s. The chinese tubes have a unique shape to the glass that's instantly recognizable. The russian tubes also have a unique look but you can't always tell the brand from the glass shape with those. My guess is they're Shuguang.

As for bias, you can safely swing between 35 and 45 mA of CURRENT in the tube. What the bias voltage would be between those two numbers I have no idea.

Just out of curiosity, did you run your receiver with the 'loudness' on or the EQ heavily adjusted? If so, it's entirely possible that your now actually hearing the speaker itself sans equalization and that sound may not suit you.

underdawg · « **Reply #42 on:** 7 Feb 2013, 01:46 pm »

MY experience with triode and ultra linear is similar. The big difference is watts between the 2 but depends on what you speakers need also. The bass seemed more present in ul versuses triode to me.

rockn · « **Reply #43 on:** 7 Feb 2013, 01:59 pm »

Quote from: kinku on 7 Feb 2013, 02:05 am

Thank you. I tried hooking up to 4 there is some change, for better. Still will not say a significant change. The sound has more balanced out now. How much change in bias voltage you will consider as a sign of impending doom?
Mine was holding constant for few hour interval when I checked today. Do not know what make Cayin tubes are . Any idea?

rockn · « **Reply #44 on:** 7 Feb 2013, 02:01 pm »

Quote from: rockn on 7 Feb 2013, 01:59 pm

i believe most Cayin amps ship with Electric Harmonic tubes.

RDavidson · « **Reply #45 on:** 7 Feb 2013, 03:01 pm »

I remember distinctly that with my A50T, the driver tubes were Electro-Harmonix. The output tubes, however, were Cayin branded. Perhaps rebranded Shuguang? Not sure.

Rex's question about running your previous receiver with the bass and treble knobs perhaps unnaturally boosted, is a great question.

rollo · « **Reply #46 on:** 7 Feb 2013, 03:10 pm »

A wonderfull synergy is had with Marantz and Monitor Audio. If you want to spend more Ayon. Give the Marantz a go you will be very suprised.

charles

RDavidson · « **Reply #47 on:** 7 Feb 2013, 03:34 pm »

Kinku just got a Cayin tube integrated very recently. You actually made this exact same Marantz suggestion a couple of months ago (before he bought the Cayin), but again haven't provided model numbers or any other useful info. If you know of a Marantz integrated that can truly compete with the Cayin, for around the price Kinku paid, I think anyone watching this board would like to know.

kinku · « **Reply #48 on:** 7 Feb 2013, 08:17 pm »

Well I bought it ,now I can not think of marantz.
I am sure cabin amps are one of the well made amps. It is just mine and not an amp problem in general. My amp is about 5-6 year old with tubes as older as it.
I am wondering if I can use 6550 tubes on Cayin A70 ( manual bias version) ? If any one knows? I know the current A70 can ,well it can take any tube

but unsure about manual biased version.

Ericus Rex · « **Reply #49 on:** 7 Feb 2013, 08:55 pm »

6550 and KT88 are electrically equivalent. You can run both tubes.

RDavidson · « **Reply #50 on:** 7 Feb 2013, 09:22 pm »

Here's some useful info from Enjoy the Music, and it looks like your amp, no matter which version you have, can use tubes of the same pentode family. You just need to know the bias setting for each, which VAS should be able to provide.

"As I advanced farther in this report my research uncovered some confusing product duplication. There are actually two nearly identical models of this same Cayin amplifier. Acoustic Sounds markets a different version and states they are " the exclusive on line dealer for Cayin Audio products" they sell a similar SA-70T Integrated Amplifier. But Acoustic Sounds lists different specifications for their amplifier. They specify the SA-70T amplifier power as having 30 watts per channel in Ultralinear and 18 watts in triode operation. A bit farther along on the Acoustic Sounds web site the manufacturer literature states that that the SA-70T amplifier uses auto bias. And provides a list of possible substitute pentode type tubes KT88, 6550, KT66, KT77, 5881, 6L6, EL34, 6CA7 and 7189A.

The integrated I am evaluating for this report is from VAS Industries the "Exclusive Cayin Importer and distributor" of the A-70T Integrated amplifier The A-70T owners manual specifies that it is rated at 55 watts Ultralinear and 26 watts triode. The A-70T will allow tube substitution using the same types of pentodes as the SA-70T but requires that you adjust tube bias manually. The power specifications of both amplifiers are rated into an 8-Ohm load using KT88 tubes and in every other way the amplifiers appear identical. Understand that substituting other types of pentodes for the stock KT88's will change the power rating for both versions of this amplifier. Additionally there is a slight price difference, the Acoustic Sounds SA-70T lists for $1,975 and the VAS A-70T lists for $1,995. I phoned VAS the importer and I was informed that the two versions of this amplifier are still available. However VAS Audio states that they import and sell only the "newer higher power" A-70T version. This audio amplifier has upgraded power transformers and costs twenty Dollars more and for me the choice between the two is the Cayin A-70T. The increased power will allow a broader range of applications and that means more system matches."

kinku · « **Reply #51 on:** 7 Feb 2013, 10:24 pm »

Davidson thanks. I been a real pain. I read this review but was not careful enough to see about other pentode tubes.

One more thing about cayin A70 currently on US market is it is only a 30w version despite what is advertised in red letters and specs say at cayinusa site. If you read the manual it clearly says it is a 30W Model using KT88. Yes you can do all tube rollings if you want to ,but why bother.

RDavidson · « **Reply #52 on:** 7 Feb 2013, 11:17 pm »

I know your head is probably swimming already just thinking of different brands of KT88's to try, now multiply that by all the pentodes listed above. Well my point is you might want to "bother" because somewhere amongst all those choices is a combination of tube type and brand that is tailored to your preference. You just need to find someone who has more experience with your particular amp. You might also look for guidance from those who have owned, listened, or reviewed the Cayin's close cousin, the Primaluna Prologue 2 and even the Dialogue 2. As the Primalunas are more popular (at least from what I've seen), I'm sure you'll find a lot of info over at Audiogon and other sources. Just Google search reviews and tubes for these 2 amps. I think Rex's recommendation of new Gold Lions is a good one. Don't be afraid to swap the driver tube compliment either.

kinku · « **Reply #53 on:** 8 Feb 2013, 06:54 pm »

Do you have any recommendations on pre amp tubes? Not the one that cost exotic money but reasonable to try ,considering the week bass. Mine currently has RCA clear tops AU7. Read somewhere it adds brightness and week on lower frequencies!

RDavidson · « **Reply #54 on:** 8 Feb 2013, 07:37 pm »

I think Psvane tubes get good reviews / good general recommendations and don't cost a lot, relative to NOS. Both their 12ax7 and 12au7 get high praise. Grant Fidelity carries them. Are they as good as the best NOS tubes? Probably not. Then again, you're not paying NOS prices and I'm sure they compete sound wise. Another solid, and truly inexpensive recommendation are new production Electro Harmonix. They're very good all around tubes. I believe Audio Research uses them as the stock tubes they send out with their amps / preamps. Give Tube Depot a call. They are very helpful with making more specific recommendations, and they carry EH. No, I am not affiliated with either GF or TD.

Ericus Rex · « **Reply #55 on:** 8 Feb 2013, 09:00 pm »

RCA Cleartops ain't slouchers. I don't think you'll get much better sound from rolling those, just slightly different sound. If you really must try something different you can get JAN (usually Sylvania or Philips, JAN = Joint Army Navy) 12AU7s for quite cheap. And those tubes aren't slouchers either.

http://www.tubedepot.com/12au7.html

Recheck your wiring and make sure the speakers are in-phase with each other. If all there is OK then try reversing the + and - on both of the speakers and see if that makes an improvement.

RDavidson · « **Reply #56 on:** 8 Feb 2013, 09:27 pm »

More good info from Rex.

I too have found Jan Philips and Jan Sylvania tubes to be very good NOS, but wasn't sure if my experience with them was universal enough to make a recommendation for you. Due to popularity and supply, prices of these have gone up significantly over the last 2-4 years. They used to be cheap, as in, about $15-$20 a tube from Tube Depot for the better examples.
Rex is right, RCA clear tops are supposed to be among the better tubes. I wouldn't change them assuming they have plenty of life.......which I'm sure they do. Driver tubes tend to last a very long time with proper use.
What 12ax7's do you have?

kinku · « **Reply #57 on:** 8 Feb 2013, 11:44 pm »

Thanks. 12AX7 are stock versions. I was thinking about getting NOS GE 5 STAR 5814A, 2 mica for 12AU7.Read good reviews about them in many places.I am not saying RCA clear tops are bad. But I read at many places they are bright and energetic which MIGHT make it difficult to listen through a bright speaker like RS6

After careful listening it seems like bass is there but overwhelming midrange just masks it ,preventing it to come out.
Bias setting 2 days ago was 0.43 V today when I checked it is 0.42 ,do not know it is significant or not?

RDavidson · « **Reply #58 on:** 9 Feb 2013, 02:00 am »

Tubes have a general tendency, in my experience, to bring the midrange forward. I think the effect can vary based on the tubes used. I'm not exactly sure what to recommend for you. Again, I would just give Tube Depot a call and let them know what you have and the goal sound you're trying to achieve.
I think your bias is probably fine. Slight variation in the reading is pretty normal. If it continues to drop after a few more days, you're probably due for new tubes.
I kinda hate to tell you this, but for $1300 for that amp, you should've had practically brand new output tubes included in the price. You didn't do too bad, just not as well as you probably could have. You live you learn.

kinku · « **Reply #59 on:** 9 Feb 2013, 03:13 am »

Images of 12AU7 tubes in my cayin. Seems like they are 5814A.Does anyone know what their makes are?