Category: – 6CA7/EL34 all types

6CA7-Z / KT88-Z or WE 6CA7Plus / WE KT88Plus – which one?

Answer to an inquiry from Germany – related to Unison Simply Italy:

6CA7-Z and KT88-Z were released over 10 years ago to the market as the very first high end upgrade tubes. But over years, the factory’s lack of quality screening has flooded market with mixed quality. We (Grant Fidelity) no longer carry them as the ‘selection’ cost is simply too high and performance varies too much. 


WE Plus series is the latest release before Shuguang factory went into relocation and ceased production in 2020 till further notice. From our own evaluation, the sound of this series is much better than previous Z-series (yes people do hear lots of good things about Z-series as they have been on market for 12 years with certainly more users). We selected through the entire factory stock and acquired less than 10 quads which meet our quality standard. We won’t hesitate to recommend them, simply just by the excellent test results we have seen on those we picked.


For your amp – i see the manufacturer website showing it uses EL34. It can be replaced with WE6CA7Plus no problem. I don’t see mentioning this amp can use KT88 – so please make sure your amp indeed can use KT88. If so, WEKT88Plus can be used. 


In general, KT88 gives more bass low frequency but resolution for midrange and high frequency isn’t as good as 6CA7. You can have to decide what is more important to your listening and choose accordingly. 


Hope this helps. 

6CA7- ‘they are exceptional tubes’

from customer Lyle C. by email:

“Greetings,
I bought a quad of the Shuguang Black Treasure 6CA7’s from you recently and love them. They are exceptional tubes, absolutely killing the EH 6CA7 and Tung Sol reissue EL34’s I’ve tried.”

‘Just buy the 80% emission Treasures and be done with it.’

Feedback from customer Gregg O. by email:

“The 6CA7Z’s arrived safe and sound.
I have about 5 hours on them and so far I think something special is going
on.
I have on hand a quad of NOS EL34’s from a very reputable source that have
150 hours on them..and so far the 6CA7 Treasures seem to have more fullness
and body to the sound without sacrificing detail.
I can safely say that if one wants to prevent stomach ulcers and headaches(
from banging your head against the wall) trying various NOS EL34’s…Just
buy the 80% emission Treasures and be done with it.

6CA7-Z Treasure tubes – recommended

Posted by forum member:

I would recommend the Shuguang Treasure 6CA7-Zs, as tested and screened by Grant Fidelity, as a substitute for the EL34s. The additional cost is well worth the better Grade A. I noticed that the heat from the Treasure 6CA7-Zs is substantially and significantly less than the heat that emanated from either the Siemens or the JJ KT77s or the EH EL34s. That thermal difference could well mean a longer life-span for the Treasures.

original post here: http://www.audiokarma.org/forums/showthread.php?p=4503443

It’s emotional..

by email from customer Kevin K.

‘Hi Rachel,

Thank You! The tubes arrived today and I can best describe them as “emotional.”  I have had the CD 327a powered on for two days now and listened to Rickee Lee Jones and The Durutti Column through the Treasure Series this afternoon and they sound very good already. Perhaps the selection of tunes has to do with the “emotional” tag; I dunno…’

‘Not sure if I can get better tubes than what I spent on these’

Comments from Simon N. in Ontario:

I have a GrantFidelity A-534 with a set of Telsa EL34’s NOS, they’re good to me compared to the stock GF (Shuguang generic clear glass) tubes, and initial thought on the black bottles, they weren’t as open and quite rough sounding compared to the Telsa’s. Burned them in more hours but still not too impress, then I left the amp on over night for good couple of weeks to burn them in. Now they sing!!! Sounds very live with these new tubes and very smooth sounding.

They also look nicer than the Telsa with the black coating on the glass. I’m not sure if I can get better tubes for what I spent on these, but they worth every penny to me!

Simon

original post here: http://grantfidelity.com/forum/viewtopic.php?t=291‘

‘they sound better than the best Mullards I have’

– from customer Richard J.

“Dear Rachel, First I would like to say Thank You for sending the Shuguang Anniversary EL 34 Black bottle tubes. Amazingly they sounded better than the best Mullards I currently have on hand right out of the box. I have never had a tube sound so good with no break in time, and I have been using tubes since 1963. Thease are trurly an amazing accomplishment. ”