The 'NEW' YAQIN MS-20L Integrated Vacuum Tube Amp Thread - Page 9

Update on the GE 5654W tubes

About one month ago I noticed a high pitched ringing sort of sound coming from the speakers (tweeters) during quiet musical passages and between tracks of songs. I gently tapped on the tubes (the 4 closest to the front) and the ringing became worse. I switched around the GE tubes and the noise was still there. Seems like the tubes are microphonic. The noise bothered me so I swapped the original Chinese tubes back in and now there is a marked decrease in the high pitched sound (barely audible with my ear right up to the tweeters) and the amp still sounds great!

I will leave the stock tubes in there for now. I may try a different brand of tube such as the Psvane at some point, but for now I'm happy.

No biggie Rob. I'm just glad that I still have half of my hearing ability left to even notice the noise. Yes I bought them from Redfern.

This is the same problem I've had.I have done some reseach on the net and found that the GE 5654W are known for this.I also put the stock tubes back
in,but found them to be to flat and hollow sounding.After reading some tweak ideas and doing a similar thing myself,I wrapped my tubes with teflon tape (plummer's tape) this made a world of difference and not only did it stop the ring it also seem to help the low end out and opened up the sound stage a little more. Just take the tape and wrap it around each tube about 8 or 9 times.
Teflon tape is non-adhesive,so no harm will be done and it's also very cheap about $4 for 6 rolls at Home Depot.Telfon tape is also very good at keeping out RF noise.

P.S. just wrap the glass not the pins

I had the windows opened today brought in a little dust.....

Hey,hey

No problems with heat..


Don't get me started on Comcast

I'll give the tape a try.
Thanks

hi everyone, new here,

i also stumbled on yaqin amplifers being sold from Hong Kong on ebay. I'm assuming this is a generic branded amplifier that is just built by some electrical engineers in asia?

Also, how often do tubes need to be replaced?

thank you

thanks so much for that fast response!

my original AMP idea was

Sonos or Computer -> PeachTree Nova -> speakers

but when I stumbled on the amp from ebay, not only did it look gorgeous, it has a lot more tubes and i can't imagine the peachtree in terms of its tube amplication portion being any better.

However, the peachtree has a DAC, so given that I will probably use a sonos or a computer, does that mean I have to do something like

*btw i don't want to use the DAC on the sonos, most audiophiles don't recommend that apparently

Sonos / Computer -> DAC -> Yaqin -> speaker

?

Hi woodstart,

"Music Source....... Pandora One, Grooveshark.com, onboard MP3s, HD, FLAC, etc. The 20L is an integrated amp."

Sorry, I don't quite understand what you mean by 20L is an integrated amp in terms of the music sources you listed, i assumed all those sources were digital and had to go through the DAC you mentioned, then onto the amp.

"HRT MSII DAC" approximately how much is this DAC? getting an idea for how much DACs are.

Is there something special about HD PC? What does that mean really?

Also, if I am going to just do digital out of my PC and use winamp for example, do I need a really spiffy sound card? I figure if my downstream hardware is good I should not right?


thanks again =)

I don't typically give input in forums such as these. I joined this thread just to put my two cents in for what I see as a HUGE upgrade. It was that important for me to provide this feedback. I have tried two seperate batches of JAN 5654W preamp/driver tube sets. One set dated 1985 and one set 1983. I ran these both about 100 hours each. I found the GE tubes to be very microphonic. Wrapping them in Teflon pipe tape did help some and I was ok doing this until my brother recommended trying Mullard EF95's mostly because he assured me the microphonics would be eliminated. These Tubes are fairly rare but I found a supplier from UK on Ebay and bought 4 matched pairs with the preamp stages and driver pairs matched left and right perfectly.

The long and short of it is the difference from the GE tubes to Mullard's is AMAZING. The cost of the 8 mullards w/shipping is about $115 US. But if you can afford it, and have a supplier that can match them, you NEED to upgrade IMO. The second set of GE tubes fully broke in (about 95+ hours) were not even in the same ball park of performance as the mullards with only 10 hours into the burn-in. My mullards have about 20 hours in them and the dynamic range, fullness of the sound and 3D feel of the soundstage is amazing. The GE tubes were very bright and sometimes harse in mids and highs. BTW - I'm running Genalex KT77's as finals (fully burned-in when i swapped the EF95's). Another amazing upgrade to the stock tubes.

I just ordered a YAQIN MS-20L in part due to research from this site.I hope you all aren't tone deaf..Looking forward to trying out tubes.This will be my 3rd system.Right now for 2 channel I'm running Bryston 3nrb with a .5 preamp and a cambridge dac playing flac .I also have a Marantz and axiom home theater set up.This will be more stuff for the wife to complain about.Plan on using some Swan Divas 5.1 with the Yaqin and a BO turntable .
Cheers Graham

Hello,

After reading this forum about 10 times a week,I went ahead and ordered the ms-20l
and the ms-12b.I've had them for two days now and (!!!!wow!!!!). The reviews from tubedoctor1971 and woodsart were so great that I knew I had to get them.
I replaced the stock 6j1 tubes with Western Electric 403b's from the 40's and the el34's
with the KT77's like tubedoctor1971 did and this took it to another level all together.
I had a Jolida JD 302B that I just sold to my brother two weeks ago,the yaqin makes the
Jolida sound like a toy.The Jolida is what I originally had the KT77's so they were nice and burned in.The Jolida produced more of a soild wall of sound alot less of a true to life sound,were as the Yaqin producess a deep natural sound stage.Vocals are just out of this world.I found myself doing to the Jolida what I always had to do with soild state amps and that's eq'ing.I just set the eq flat with the Yaqin and it's all there the way it should be.The same holds true for the ms-12b it's just as great.Thanks you woodsart and tubedoctor1971!!!!!

i'm "selectively deaf", at least according to my wife...

btw, if anyone wants one of these and they are located near southern new jersey, drop me a pm...

^^^

hey rob...

actually, i'm thinking about it... i might drive down there for a day, it's only about 3 hours from the toxic waste dumps...

if so, i'll let you know... we can get together for a "beverage"...

I received the 20L yesterday.Soon as I took it out of the box I could see how solidly built this amp was.Even the remote is heavy.For sources I used a BO beogram rx with a mm3 cart with a cheaper ebay special phono pre.The cart was replaced by me just as I stopped playing LPs in the late 80ies so it is virtually new. I also hooked up an old Nad 505 thru a cheap Super Dac.The speakers I used are a set of Swan Divas 5.1 floor standers.Needless to say I need to upgrade the cd player and at least the phono pre(maybe a Yaqin)
I started by letting the amp warm up for 30 minutes.I then started with cds.Initially i was impressed.It sounded comparable. to my bryston system as far as quality goes.The sonics seem to improve as the amp continued to warm up.I listened for 3 hours then shut it down till later in the evening.I started to clean albums and spin them after supper.The vinyl sounded good thru this amp even with the cheap pre.Ended up playing tunes till 2 am.All I can saY THAT THIS WAS MONEY WELL SPENT

What a great thread!! Read every single post. Appreciate it.

Probably will get one but have a few questions:

1. In UL mode, does the 20L and 10L sound the same? Since there seem to be concensus that the UL mode sounds better than the triode, then don't seem to need the triode mode. Yes, there are other features of the 20L but I'm simply wondering about how it sounds as an integrated amp. I think I found my tube amp...

2. These are manual biasing right? How difficult is it to bias correctly as you guys tube roll? I've never had a tube amp yet.

3. I'd like to run these 2.1 which is a problem as I think there's only one output on the 20L. Any suggestions? I'd like the output to speakers to reproduce above 80hz and the subwoofer to reproduce under 80hz. My source is my laptop through a USB DAC such as the Music Streamer II.

4. Any sense how this compare with something like the the MingDa MC34A06 that Pacific Valve think is the best sub $1k amp? The Mingda cost a fair bit more than the 20L.

Thanks!

UL

I will echo Rob's opinion about the HRT Music Streamer II! For any one looking for a USB only DAC strictly for Computer music listening, the HRT is hard to beat at any price point. There are high end DACs that people favor more and in fact they do have their benefits such as quieter background, separation, detail and smoother signature, however keep in mind that these are extremely tiny improvements in S.Q. And depending on the quality of your gear, perhaps not noticeable at all! Not to mention you will be paying in most cases 10X the cost to obtain! If anyone is curious for comparison reasons read the "Great DAC shootout" on AudioCircle as the Music Streamer II was a surprise performer to say the least in the company of many high end DACs and according to the opinion of some the HRT was the 3rd best sounding DAC and the winner was the Tranquility DAC at a cost of over $1000.00 For those that think Asynchronous or high resolution 24bit 192kHz DACs have better sound quality? Guess again, because the Tranquility is a regular old 16bit 44kHz NOS DAC! I think the S.Q. Has more to do with the Analog section of these DACs then anything else because nothing else explains the improvement in sound quality save for the lower Jitter of the NOS design. This is what Steve from Empirical audio explained to me a long time ago. He was actually trying to save me money. He designs the PaceCar and OffRamp components which are supposed to help tremendously with Clock management which minimizes Jitter. The V-lab is also a NOS or Non Over Sampling DAC and many people swear by the analog sound it outputs.
I have heard that some people like the M.S.II but still hear some digital artifacts compared to higher end units that have a smoother signature, I disagree and think that the Music Streamer II is very analog sounding and I was using it strictly with Solid State gear until I got my Grant Fidelity B-283 buffer. In any case if any of you are using tube amplification with the Music Streamer it would be a great match if in fact there are digital overtones to your ears. If any of you want a DAC for anything other then USB computer audio you will have to look at a DAC with Optical or S/PDIF connections as most CD players, Transports, Amps and AVRs do not have USB inputs. The USB to S/PDIF converters will work with some USB only DACs and the good ones convert up to 24bit 192kHz resolution. I think that's adding more to the chain and common sense dictates a quality DAC with all the features you need in one unit!