ECC81 or CV4024?

[Jay]

If you were to choose between Mullard CV4024 and Mullard ECC81 (limited)?

 

[316a]

12AT7

CV4024 have far better availability than standard ECC81 and as a result , should be cheaper . The going rate for Cv4024 in the UK is about £8 per tube . However if you purchase CV4024 , ensure the tubes are tested and matched . There appears to be more batch variation than standard commercial ECC81 . About 25% of the CV4024/M8162 I have tested also show >15% sectional imbalances , even after burn-in so if you buy these , choose the vendor carefully .

316a

 

[siu sin man tho]

hi jay,

if budget averable choose gec a2900.
then U not need to make any choice in the future.

thnaks;

thomas

 

[316a]

A2900

Jay is in Indonesia and needs more than 10 for a project . A2900 will break the bank and the import charges for 10 A2900 will add even more . You must have plenty of money to spend in HK if you're recommending tubes such as this !

316a

 

[Jay]

6J5 = 1/2 * A2900

There’s no problem spending $$$$, as long as nobody else is able to create comparable result from $$. It will be painful to have an expensive gear but the performance is not better than another or someone else’s cheap gear.

As an audio system consists of not only a preamp, I will prefer buying a better loudspeaker than buying 10 A2900. It’s not about the price. It’s about what I think I will get with the money.

I’ve already assembled a power supply along with the tubes. The transformer is 2X250V or 2X300V. I also have bought 2 Mullard CV4024. I’m now thinking of the possibility to build a 2-gain stage preamp using the Mullard and RCA 6J5. All tubes are military grade. The 6J5 is half the A2900 price, but the most important thing is, I know where to find it, I know how it "sounds", and I know many audiophiles also like it.

 

[siu sin man tho]

hi jay,

If U choose 6j5 why not considerate 76.56 or 26 tube.
26 is the best & low price but a little bit trouble to handle the hum. 26 is a DHT.
The triode sound was detail that above,
try to considerate.
I try this type 1960's military china 6sn7 & cost only USD 10~12 per piece.
NOS & 100% brand new. I got 1000pcs & prepare to kit use.
Hope more Diyer will love them.

thanks

Thomas


www.diyaudiocraft.com

 

[siu sin man tho]

hi jay,

If U interest for 6j5, try to click my friend;s website.
he use
DIY PRE-AMPLIFIER: 6J5 with Transformer Output

his web. http://www.vt4c.com.

I was search in the old stock for 14950~1960 china military grade tubes. Hopw 12at7 can find wthin USD 6 NOS brans new one.
Every tubes I will test the Ia & Iv.
I will fully matching them within 1%.
They were coming......................

thanks

Thomas

www.diyaudiocraft.com

 

[316a]

Good luck !

I rejected almost the whole batch of 100 'military' T grade Chinese 6SN7 I received a while ago . AWFUL ! Very poor matching (>20% imbalance) , electrode leakage , low emmision and grid current were the main problems on the majority = not good , you may get 20 out of 1000 with 1% matching if mine were anything to go by . Took me a lot of time to test the batch too , never again . Luckily I was credited with a refund , hope the ones you bought are better . The vendor is still selling these too !

316a

 

[siu sin man tho]

hi 316a,

this is not the 6n8p that u choose, its from nanjang.
not the T,J that previous can buy.
pls study.
The J,t, was new build tubes.
not nos.

thanks

Thomas