yaqin ms-22b and/vs HK730 Twin Powered

sosico

New Member
Hello everyone,

I have been trying different vintage equipment over the last couple of years and I really like the sound of the HK 730 twin powered. I have always wanted to experiment with the tubes. Lately I have been listening music through my vinyls only when I'm home for which,I decided to give a try to the yaqin ms-22b which arrived two days ago. I have been using it for two nights and so far I'm dissapointed with the sound. I think that the highs are not very clear and too bright and something is missing in the middle. When I go back to the HK 730 phono input , it sounds better.

I was hoping that using a tube phono preamp will sound better than the SS phono input. Is there something I'm missing here? Is there any AK member using a HK 730 and Yaqin? If I change the original tubes that came with the Yaqin will I hear a clear difference in sound?

Thanks!
Nelson
 
There is aso the question of tube burn-in. I have a Yaqin amp and phono stage and find them quite good and pleasant to listen to. As the previous poster mentioned, they should sound better with a tube amp.
Then comes the horrible addiction of tube rolling (trying different tubes which often changes the sound of the piece of gear in question)
 
Thanks for the reply.

The HK 730 is solid state. I have just changed the tubes on the yaqin, I had some old telefunken 12ax7 around and now I like how it sounds very much. So it seems the problem were the chinese tubes that came originally with the yaqin.
 
Thanks for the reply.

The HK 730 is solid state. I have just changed the tubes on the yaqin, I had some old telefunken 12ax7 around and now I like how it sounds very much. So it seems the problem were the chinese tubes that came originally with the yaqin.

It's not just the tubes , which do help, but it does require some break in. Give it 20 hours or so before you start to get some decent mid range. I had the same issue but it's gotten better.

That being said I really miss my JD9 II!
 
It's not just the tubes , which do help, but it does require some break in. Give it 20 hours or so before you start to get some decent mid range. I had the same issue but it's gotten better.

That being said I really miss my JD9 II!
The stock Chinese tubes are perfectly matched but compared to even the cheapest old production 12ax7 they're junk. Have bought the Pavane and Gold Lion reissues with gold pins yet they don't even have something as basic as copper grid posts!!

The best way to test phono tubes is to record to audacity the same song for each tube type. Play back over and over. Even visual cues like the audio wave spikes will look flatter or rounded off with new production tubes. This is unlike the old stock tubes show which better detail. And as a MS22b owner, recapped HH Scott phono sections have better midrange and are quieter.
 
Hi Nelson, the disappointing sound is due to the way the RIAA circuit is implemented in the MS22-B and MS12. See http://homepage.ntlworld.com/lez/Yaqin MS-22B/Putting 'Life' into the Yaqin MS-22B.pdf

Not sure where you are but if you are prepared to pay postage I will convert the unit for you for free. If you want to contribute towards components is up to you.
Last one I converted received the following comment:- "Fired it up this morning and have played 4 lps so far- Wow! Doesn't come close. I use my gear to do 24bit 48k digital transfers and was able therefore to A/B comparisons.
So, more detail- am hearing stuff in the mix I didn't know was there and most important a kind of distortion/digital fuzziness is gone esp on vocals which is always the test for me (I was a minor sound engineer for a while). I was about to give up- but now I am enjoying the music again.
Thank you SO much- this is an amazing job - I will definitely brag about this"

Regards, Les
 
Hi Les, and thank you very much for your offer. I sent you a private message to see if we can arrange something. I would really like to modify the yaqin


Hi Nelson, the disappointing sound is due to the way the RIAA circuit is implemented in the MS22-B and MS12. See http://homepage.ntlworld.com/lez/Yaqin MS-22B/Putting 'Life' into the Yaqin MS-22B.pdf

Not sure where you are but if you are prepared to pay postage I will convert the unit for you for free. If you want to contribute towards components is up to you.
Last one I converted received the following comment:- "Fired it up this morning and have played 4 lps so far- Wow! Doesn't come close. I use my gear to do 24bit 48k digital transfers and was able therefore to A/B comparisons.
So, more detail- am hearing stuff in the mix I didn't know was there and most important a kind of distortion/digital fuzziness is gone esp on vocals which is always the test for me (I was a minor sound engineer for a while). I was about to give up- but now I am enjoying the music again.
Thank you SO much- this is an amazing job - I will definitely brag about this"

Regards, Les
 
Some of the comments received by those who have converted their MS22B's and the first comment is with respect to a MS12B!

"Oh man this thing can really sing now. Joni Mitchell is standing in front of me and singing live at my home. .
Thank you Les. You are the man."

As you said, Les is the man. Besides creating the write-up that describes the work involved, I know that Les has helped numerous individuals personally (including myself) with the conversion. Thank you Les for everything, I want you to know that my LesBox is working flawlessly and is still f***king awsome.
I absolutely agree with another converter when he commented "I can't imagine ever buying another phono pre".

"I understand that Jazz usually sound good through tube electronics, but rarely I heard such a speed and timing for rock/pop from a tube phono-pre before. It is truly an amazing experience to listen to this phono now. "

"During the week I had my MS-22b returned after the Hi-Q mods. I have been listening at every chance since and my first impressions still hold. This is what I thought then: "The amp arrived yesterday so I was listening till late night and it sounds excellent. More musical and 3D with instruments spread out across the sound stage. I like lots of different types of music from rock to jazz and tried them all. So as you might guess I won't be returning it for the mods to be reversed."
As my ear has become tuned to the new sounds its even better than that. I'm now hearing things in recordings that I didn't know were there in the first place. A great job."

"Another MS22B rebuild by Les (Hi-Q) - apparently Yaqin had fixed the hum on their latest model - but with the extra tube and a host of new components as detailed in Les' comprehensive PDF guide the difference is literally between Night and Day. I was somewhat underwhelmed with the original unit - now I'm hearing stuff in the mix I didn't know was there and a kind of brittleness most noticeable on vocals is essentially gone - I'm back to enjoying my vinyl. Thanks to Watford's DIY audio genius!"

"Fired it up this morning and have played 4 LP's so far- Wow! Doesn't come close. I use my gear to do 24bit 48k digital transfers and was able therefore to A/B comparisons. So, more detail- am hearing stuff in the mix I didn't know was there and most important a kind of distortion/digital fuzziness is gone esp on vocals which is always the test for me (I was a minor sound engineer for a while). I was about to give up- but now I am enjoying the music again.
Thank you SO much- this is an amazing job - I will definitely brag about this"
 
Les,

I have a Yaqin MS22B heading my way sometime next week and I am very interested in your mods. At the present time I am using an ART phono preamp, which surprisingly for it's price, sounds very good to me. Still, there is always room for improvement and I hope this Yaqin provides that.

I just retubed my Yaqin 13S amp with Tung-Sol 12AX7's & Tung-Sol 12AU7's & Svetlana SED winged "C" power tubes. It was a significant improvement over the stock Shuguang tubes. Along these lines, do you have any suggestions for retubing the MS22B?

In one of your blogs, I think you mentioned putting a kit together for all the parts needed to perform your upgrade. Did you ever get around to that?

I'm somewhat nervous about doing the upgrade. I haven't touched a soldering iron for many decades, but your instructions seem very clear. Actually, the work you did on this preamp seems very impressive to me. It's not just a mod, it's an entire rebuild.

One last question...

In your own words, after the rebuild, how do you describe what changed from the stock unit?

Anything you say will be greatly appreciated! I hope we can keep this discussion going.
 
"do you have any suggestions for retubing the MS22B?" I was recommended to try svetlana winged =c= 12AX7's with long shiny anodes, these are terrific especially in the higher frequencies and currently at a bargain price http://www.ebay.co.uk/itm/310215317249?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 but it is all down to ones listening taste really.
"how do you describe what changed from the stock unit?" Well I put the replies from others in the previous post and they all say what I found when I did the conversion.

The story starts some years ago when I built my own hard wired pre-amp to the same circuit but tried over the years to build solid state versions which never sounded the same. They all met the same if not far better RIAA curves but for some weird reason, the listening tests just did not hit the mark and I went back to my faithful valve version. I knew about the MS12 and MS22 but having a good working unit of my own it was hard to justify the expense even though the reviews talked and still talk about the amazing performance of these units. Then one day, someone offered me his MC10-T amplifier at a good price and threw in for free an MS22! This I thought would be a tremendous bargain and I had some friends round to witness the amazing sound the MS22 was going to give. To say we were all so disappointed would indeed be an under-statement, the MS22 was losing so much detail that after 10 minutes my friends pleaded with me to re-connect my home grown pre. So I decided to use the metal work for a new build of the home made unit, using the PCB if possible as the two valves needed it for their physical support. The circuit required a high impedance to the Buffer so I replaced the original transistor with a mosfet and it worked! But there was still something missing, you could tell by the sound of the click as it made initial contact with the vinyl! How could this be? All units agreed fully with the RIAA and it remains a mystery, defying all attempts to measure it with instrumentation. The thing that was missing was the extra valve in place of the mosfet, fitting this brought back the full magic.
Steven, if you feel happier for me to do the conversion I am quite happy to do, the postage costs are high but I am happy to help pay the return costs for you. The parts cost roughly 25GBP, labour is free as at the moment this is a hobby for me not a business. If you want new winged =c= fitted then another 40GBP. All I ask is that you use the MS22 in its present state for a while on a test record of your choice so you can get an idea of how it sounds. Then you will have some idea of how the new circuit has opened up the whole spectrum of sound and particularly the sound stage. I will try to send a private message to you with regard to mailing address etc.
 
I would like to update everybody regarding the Yaqin conversion. Thanks to being contacted by lilc here in the forums, telling me how great his LesBox conversion sounded, I contacted Les again to do the conversion myself. He was very helpful and sent me some parts I could not find here, and guided me through the process of the conversion. I can tell you the difference in sound is amazing!! I'm very happy with the LesBox, I cannot thank enough Les for all the help and for creating the document to convert the Yaqin, he is a genius!
 
Damn, I returned the stock 22b I purchased earlier this year as it didn't sound good to me, despite rolling in some trusted tubes. Now I see Les's posts and kinda wish I let him tweak it first.
 
Putting ‘LIFE’ into the Yaqin MS-23B

I recently bought the yaqin ms-23b for two reasons. 1, because reading online it sounded like a good budget buy... and 2, because everywhere i read about it, i kept seeing "LesBox", "Les Carpenter", or "Hi-Q". basically any forum you get to about this preamp, his name will pop up regarding his modification to the unit.

He's created an entire PDF (here) discussing how to diy this. i was a bit hesitant, seeing as i've never soldered, dremeled, nor have the tools. so i took the next step, and contacted him on AudioKarma, to see if i could pay to have him to do it for me.

Long story short, Les wouldn't take my money, modded the whole thing for me, and shipped it back to me (from the UK) on his dime. couldn't be a nicer guy on the internet. not only that, but kept in contact the whole time he had it, on what exactly he was doing, how the mod was going, etc.

He recently shipped it back to me; here is the unboxing (with my terrible camera-phone).


ukb7gcy.jpg



personalized letter that came with it!
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component checklist of my device
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RIAA graph
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showing the changes from original to his mod
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more explanation of what was modded
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also came with a "LesBox" keychain
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he even sent back spare/extra parts
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now to the actual device (with the 3rd tube added!)
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i cut the tube-guard so it would fit the 3rd tube while Les had it
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yaqin with tube-guard on
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plugged it in (rtj2 ftw)
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listened to 3 albums on it last night
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all 3 sounded immensely better than it did while it was stock.
daft punk... amazing. but the jazz/horns on sonny rollins and miles davis. sooo good





tl;dr
the lesbox is the best thing i've done for my new turntable addiction
 
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Clarity. Its so much less muddled... You can hear every instrument on its own. There are literally some musical parts to my jazz albums (and peter tosh) that I didn't even know were on the record.

And yes I did. I had used it for about a month prior to contacting him. And I was happy with it. But now it sounds like a $1k pre, instead of a $250 pre.
 
Hi-q,

I am looking to purchase a yaquin ms23b. Would you still be interested in modifying that unit? I live in Kansas. I need a phono stage. Your idea interests me.
 
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