[highstream]

How are they working out for you?

Due to water damage, my living room became a storage area for a couple of months. I found the Orange Globes too warm. I’m back to the 6N23P, with current WE300B’s in the dac, after frying some excellent EML Anniversary 45’s with the wrong voltage setting.

 

[Ufanco]

Hi my amp can use either the 6DJ8 or 12bh7 tubes. Already invested a bit into the 12bh7 tubes but was wondering how they compared to the 6DJ8 line of tubes?

Would I see any improvements by using the 6DJ8 tubes compared to the 12bh7.

 

[Ufanco]

Ended up buying some Hewlett Packard Amperex ECC88 6DJ8 halo with green tips to try out. I figure they should be good enough to compare them against the 12bh7 without spending too much. They were $20.00 a tube so any thoughts on them would be appreciated.

 

[Shane D]

Ended up buying some Hewlett Packard Amperex ECC88 6DJ8 halo with green tips to try out. I figure they should be good enough to compare them against the 12bh7 without spending too much. They were $20.00 a tube so any thoughts on them would be appreciated.

Are they matched, or do you only use one at a time?

 

[Ufanco]

Not sure if matched there tested readings are close and bought 3 in case one had issue. Figure I can return the extra one or just keep it since they were cheap. I think the green tips are suppose to have more rigid testing. The HP are made my Amperex and once have them I should be able to better read date code. To me they look a lot like the early 60’s?



GM1 = 11,000
GM2 = 11,750
Hickok minimum = 7750/7750

GM1 = 10,250
GM2 = 11,250
Hickok minimum = 7750/7750

Test results:
GM1 = 11,250
GM2 = 11,250
Hickok minimum = 7750/7750

 

[Ufanco]

Just a follow-up. Received the HP 6DJ8 tubes there all the same date codes from 1962. Overall great sounding tubes excellent low and midrange but brighter than the normal 12bh7 rca dimple tubes I have been fond of.

Going give them a few more days before comparing them with my favorite 12bh7 tubes. Might try switching from my silver iem cable back to the copper one to see if can more balance the brightness on the 6DJ8. I have mixed feelings, in some ways like the extended upper end of the 6DJ8. Depends a lot on the song and how well the recording is.

I ran across this magazine article on the 6dj8 and thought others might be interested in it so here is a link.
https://worldradiohistory.com/Archi...m-Tube-Valley/Vacuum-Tube-Valley-Issue-07.pdf

 

[highstream]

You didn’t say if these are NOS or used and, if the latter, when last used. In either case, an extended burn in period is needed for them to stabilize sonically. 150 hours at least for used and 275-300 for unused. That’s not playing time but time on, which makes it easier. Patience counts with good quality audio.

 

[UntilThen]

I’m back to the 6N23P

This is good stuff. I'm using it in my amp now.

 

[Ufanco]

You didn’t say if these are NOS or used and, if the latter, when last used. In either case, an extended burn in period is needed for them to stabilize sonically. 150 hours at least for used and 275-300 for unused. That’s not playing time but time on, which makes it easier. Patience counts with good quality audio.

Very good points on the tubes needing burning in. I posted there testing results They where listed as tested nos but I don't have a tube tester so who knows? The seller was VTS (vacuum tube supplies) on eBay.
This is also the first 6dj8 tubes I used with the amp. It can use both the 12bh7 and the 6dj8 tubes. I have to switch amp settings to use the different types so could be the circuits or something that also need some burn-in on the amp?

 

[highstream]

I suspect those settings determine the amount of voltage going to the tubes. If so, I wouldn't think it would be a matter of different circuits.

 

[TheR0v3r]

This is such a great thread, learned so much. Thank you

 

[Ufanco]

Well took the plunge and picked up some 7308 tubes. Bought a pair of Amprex from 1962 and Mullard 1969/1970. Both sets sound great.

Thought that would be my end to buying tubes but ended up finding a great deal on some 6922 tubes so guess will be set on tubes for a long time.

 

[CAJames]

...Thought that would be my end to buying tubes but ended up finding a great deal on some 6922 tubes so guess will be set on tubes for a long time.

My experience is buying tubes is seldom about need. Just sayin.

 

[rickles]

A bit of a resurrection on this

Has anyone compared the CCA from the 1970s like these? https://www.thetubestore.com/siemens-cca-6922? They're asking a fair bit for them, so wondering how they compare. Also looking at Brent Jesse's Mullard 1970s 7308 / E188CC RTC tubes. Any thoughts on either of these?

 

[Schelp san]

I was recently testing some Siemens in my T2. The CCa silver shield from your link are good tubes, but I did not find them outstanding. The asked price I find way too high. I also tested Siemems E88CC silver shield A-frame getter, which I found similar to the CCa silver shield. I returned both.
IMO the real deal are the Siemens grey shields from the 60s. In my T2 I have now a pair of CCa grey shields and a pair of standard E88CC grey shields. They are exactly the same tubes, just that the CCa are the best selected ones. Between my two pairs I could not find a big sonic difference (tbc, as I have them just since few days).
The grey shields are very dynamic and precise sounding, very tight and in comparison slightly on the leaner side. I can definetely recommend them for T2, they are awsome.