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Shuguang Treasure tubes....

I'm not sure if this is in the right place but this is about the tubes in my amp so here goes....Has anyone else given these Shuguan Treasure tubes a try?

I recently bought a used tube amp(VAC Phi 110) and the tubes that came with it were shot so I started poking around for some new tubes. I was looking for some Shuguang tubes, which are what I believe VAC supplies as standard/stock, and ran across Shuguangs limited production Treasure tubes. I poked around and did some reading, found a review or two and decided to give the only distributer for N. America(Grant Fidelity) a call. I spoke to a very kind and helpful lady who was patient with me(quite the task I might add!), was very nice and helpful and was darn knowledgeable on the tubes. Before I knew it my wallet had leapt out of my back pocket and I had splurged and ordered a matched quad of the Treasure Tubes, KT-88s. Within a couple of hours I had a tracking number and about a week later a box labeled "FRAGILE: GLASS!" was waiting for me when I got home from work.(A quick side note; during the short wait for the Treasure tubes to arrive I was using a borrowed quad of stock VAC KT-88 tubes and they were wonderful, great sounding tubes that I could live with forever....or that is until I found the Treasure tubes anyway.)

When the Treasure tubes showed up I ripped into the box and was shocked to see that each pair comes in a really nice presentation box with each tube very well protected in a foam insert, very classy. I removed the tubes, admired their beauty(they really are sweet looking tubes!) and popped them in the VAC and let them warm up for about 15-20 minutes. I then set bias on them and hit the play button expecting the usual tube break in time-wrong!...right out of the box these tubes sound fantastic! Seriously, I am shocked how at just good they sound fresh out of the box. Smooth clean highs, strong deep bass and all the other audiophile words we so endear. If they're this good right out of the box I can't wait until I get 100 hours or so on them. I'm no reviewer but I can say that these tubes offered a noticable improvement in my system and are worth every penny of their asking price, no doubt about it! So far they are chugging along and sounding beautiful and hold a rock solid bias, ZERO fluctuation.

Please understand that I have no affiliation with Grant Fidelity but when I run across a company that treats their customers so well and offers a product that performs at this level I feel I should share my experience with others, I'm one VERY hapy audionut!

Yes I actually do have a question and here it is; They(Grant Fidelity/Shuguang) also offer a 6SN7 substitute called the "CV-181", this is supposed to be a direct replacement for standard 6SN7's and I'm very interested in those as well. Has anyone else had the opportunity to give these tubes a try? Thanks for your replies.

Sincerely,
John
johngp
jcspinks
17 posts
 
Good points. I now wonder how much of changing sound due to selection of driver tubes (for me 6SN7s & 6SL7s) is that they also affect the power tube idle current (hence operating range) by tenths of of mAs. Previously I had not reset bias on the power tubes when rolling drivers. For these driver tubes with twin triodes, each power tube is tied to only one of the triodes in each tube for my amps' push-pull design. Any inequities in the triodes and any delta gain relative to the reference drivers seems to affect the measured current.

After the Shuggies reach equilibrium I will reexplore interactions with drivers and power tubes, checking both sonically and for associated changes in idle current.

Now at about 225 hours...
jcspinks
17 posts
 
I have more than reached 300 hours and have only listened briefly due to other issues, but what I have heard is very, very good. Properly biased, very fine level detail without being too forward and very deep and pitch-defined bass. The RCAs thus far are a very good match, giving luscious midrange that the Shuggies execute faithfully, again provided bias is perfect. More detailed reportage and comparison to NOS soon.
jcspinks
17 posts
 
The Shuguang 6CA7s win The contest by a nice margin. I compared the NOS Siemens with the same bias that I had optimized to two weeks ago to my latest settings for the Treasures. The Treasures are much more well articulated with excellent detail, great midrange and bass hitting hard with no fluff at all. They are simply exquisite! I am currently still using wartime RCAs as drivers with great results. I have tried many others and got some good sound, but since break-in I always came back to the RCAs and 33.3 mA of bias for the sweet spot. Absolutely the best sound I have yet heard out of two speakers.

The break-in was long and tedious but more than worth it. Give Ian your money NOW and you'll be glad you did. Case closed. Now I'm going to need reserve quads and I'll go broke.
johngp OP
222 posts
 
Hi Jcs,
I've followed along as you posted your progress, thank you for keeping us updated-fine job sir!

I've been enjoying the Treasure tubes immensely and they've only gotten better but now I seem to have developed some sort of biasing problem with the VAC so I guess it's off to Kevin for repair. Oh well, hopefully it's not gone long.

Anyway, thanks for your VERY informative posts, I've enjoyed reading them. Hopefully more people find this thread and discover for themselves what great tubes these darn TT's are!!

Best,
John
jcspinks
17 posts
 
Yup. I was really surprised at how far they have taken the sound. I thought the system was resolving before, but this an altogether new level. Even from the other room I am hearing things in familiar recordings that I had not heard before. Somehow they manage detail without sacrificing liquidity and warmth AND bass drive. It's really quite stunning. Also Nels in his article at enjoythemusic was less thrilled with the 6ca7s mostly due to relatively less bass solidity compared to the 88s. There is NO lack of bass power, pitch definition, or clarity here. It is producing some the most hard-hitting yet somehow elegant bass that I have yet heard.

Considering that they are a fraction of the cost of a good amp but are responsible for an enormous amount of sound quality and refinement, I'd say that they are a bargain given a reasonable useful life. I am getting a Hickok 580 that I will have gone over by Roger Kennedy here in SoCal and willonitor their measurements over time.

By the way everybody, absolutely play with bias because it REALLY is responsible for the final sonic signature. A half milliamperes significantly alters the sound. My other strong advice is to get your power right. The psAudio PPP made an enormous difference in refinement. And yes, fuses can matter too. They are clearly audible changes akin to power cord changes.

All that aside, the Shuggies rule.
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