[rnros]

  I've been really enjoying these a lot so far, great detail retrieval and dynamics in my Mjolnir 2.  Now I'm wondering how they work.
 
The specs are not the same for the 6922 and 5670 tubes. That'ss not to say that one cant plop in a 5670 into a circuit designed for a 6922 with a pin-out adapter, and the 5670 would not get harmed because its usual operating points (plate voltage and plate current) are such that there should be no danger of damage. The only parameter that is of very minor concern is the 5670's  15% higher Heater Current consumption. (350mA vs 300mA).
 
I have a feeling that there is something more than just a noise suppression capacitor in the iFi adapter, because to operate the 5760 at the 6922's plate voltage of around 100V (normally 150 V for the 5670) they would be affecting the 5670's prescribed bias current. 

I don't believe the increase in heater current is an issue for the MJ2. Two points: The E188CC (335mA) is used all the time in the Schiit DC heater amps without issue. Also, I believe the limitation for heater current for this amp is 425mA. At the moment I don't remember where I received this information... Email with Nick @ Schiit, Jason on Head-Fi? Quick email to Nick would get you a fast answer.
 
On plate voltage, several different tubes are being used with different plate voltages, but I cannot give an intelligent answer as to why/how the amp circuit compensates, or how a different plate voltage affects the tube performance, although different plate voltage curves are given in the datasheet.
 
If you find out anything more about the adapter being used here and internal modifications, post it here, I'm curious.
 
I am using this tube with just the usual adapter base for this group. (Well, that is to say, I've given it some comparison listening with some other well-known tubes.) I did not expect it to perform as well as it did. Another candidate for the HS (Holy Schiit) designation. For what this tube gives at the current price, definitely a 'Holy Schiit' tube. By the way, although this tube can be purchased for $4 plus shipping, you will also need the adapters, about $20 with shipping, so a few tubes for matching and adapters will run you $40 to $50. I think the $99 for a matched pair is a good price. No hassle, no work.
 
To my ear, I do prefer the WE396A above this tube, but the WE396A is about $50. However, above both of these tubes, I favor the Reflector 6N3P-E (requires the same adapter), which to me was my first Holy Schiit tube. Beautiful sound and impressive construction which can be had for $2, including shipping, if you buy a handful or more, or about $20, if you buy a matched pair. The Ultimate Holy Schiit tube!

 

[rnros]

Question: could I experience the same sound by purchasing a 5670-6922 adapter and a pair of NOS GE5670 tubes? Does the ifi adapter offer something that a boutique adapter doesn't?

Honestly, I don't know about the "same" sound, but you will experience good sound. See previous response.

 

[iFi audio]

 
I've been really enjoying these a lot so far, great detail retrieval and dynamics in my Mjolnir 2.  Now I'm wondering how they work.


The specs are not the same for the 6922 and 5670 tubes. 

Hi,This is true, however real tubes also show a significant variance from notional parameters specified in the datasheet.


In reality, the match between 6DJ8/6922/ECC88 and 5670/396A/2C51 is close enough that they work even in quite twitchy fixed bias circuits.

 
The only parameter that is of very minor concern is the 5670's  15% higher Heater Current consumption. (350mA vs 300mA).


 

Actually, various datasheets for the 6DJ8/6922/ECC88 group of valves (including Sino/Sov copies) show heater current ratings of up to 365mA maximum (see link).


http://www.jonsnell.co.uk/images/sylvania-6dj8.pdf


The 5670 is tightly specified for heater current (more so than the 6DJ8/6922/ECC88 group). Any Amplifier/Preamplifier/DAC using the 6DJ8/6922/ECC88 Group tubes should provide enough heater current for the stated maximum and should work fine with the 5670.


Cheers.

 

[Rowethren]

iFi audio I tried the UK dealer links on your website but I couldn't see anyone that stocks these. Any idea where I can get hold of them in the UK?

 

[iFi audio]

@iFi audio I tried the UK dealer links on your website but I couldn't see anyone that stocks these. Any idea where I can get hold of them in the UK?

 
Hi,
 
01900 601 954 - Select Audio
 
They will assist. Ask for Stephen!

 

[Rowethren]

Hi,

01900 601 954 - Select Audio

They will assist. Ask for Stephen!

Thanks! That was a damn fast reply

 

[iFi audio]

Thanks! That was a damn fast reply

 
You can email them too:
 
info@selectaudio.co.uk
 
But usually MCRU or Analogue Seduction or Future shop have these in stock. They should stock them if they are sold out - quite obvious really!

 

[Rowethren]

   
You can email them too:
 
info@selectaudio.co.uk
 
But usually MCRU or Analogue Seduction or Future shop have these in stock. They should stock them if they are sold out - quite obvious really!

 
Spoke to Select Audio and I have a set on the way. That is some serious CS you guys have there!

 Looking forward to them arriving in the next few days. 

 

[iFi audio]

   
Spoke to Select Audio and I have a set on the way. That is some serious CS you guys have there!

 Looking forward to them arriving in the next few days. 

 
Thank you - really makes our day as we usually dont receive compliments!
 
Whilst you are waiting for the NOS6922, make sure you read the pdf here:
 
http://www.head-fi.org/t/784809/ifi-nos6922-valve-tube-upgrade-set-new-product-announcement#post_11998540
 
It is really quite fascinating.

 

[Rowethren]

   
Thank you - really makes our day as we usually dont receive compliments!
 
Whilst you are waiting for the NOS6922, make sure you read the pdf here:
 
http://www.head-fi.org/t/784809/ifi-nos6922-valve-tube-upgrade-set-new-product-announcement#post_11998540
 
It is really quite fascinating.

 
Had a read of it but I am not really too up on the technical side of tubes so it didn't mean a huge amount to me sadly. My tubes arrives safely though which is great, got fantastic service from Select Audio as well which is always good so thanks again for the recommendation. So far they seem to sound really great in my Lyr 2 smoothed the treble but kept all the detail, noticeably expanded the sound stage and added a nice bit of kick to the bass. One thing which is interesting is they seem to run cooler than other 6922 tubes that I have tried which is a real added bonus this time of year. Also I think they look great, the smaller size makes them look really cool in my opinion and the silicon adapter is finished much smarter than the socket saves I have used before. Not the best photos ever but these give you an idea:
 

 

 

[ThurstonX]

For those in the U.S. thinking about buying these, I'm happy to report that Music Direct finally shipped my order four weeks after I placed it.  That's on the short end of the 4-6 weeks they list on the product page.  They shipped FedEx Home, too, which is nice considering shipping was "free."  So perhaps they'll have some available for immediate shipping now.
 
Psyched to give them a try, esp. against the 1970 (or 1971) CV4108s I using now.  I've got a decent collection, but these 4108s are my favs of the moment.

 

[tbish]

I just received my pair from Music Direct after a month of backorder! I've only listened to them for a couple of hours in my Mjolnir 2 and I have to say that I really like them so far! There is definitely some very solid bass to these! I'd say the mids are a touch warmer compared to Schiit's LISST, and although I prefer a bright sound, I feel like these are about perfect for me. The treble is a little smoother without sacrificing any of the detail and the soundstage opened up quite a bit. This will definitely be my main tube!
 

 
I thought it was pretty cool that these came with a pair of white cotton(?) gloves! That was a nice surprise!
 

 
As an aside: These tubes have a brighter light than any of the 6922/E88CC's that I've rolled. Looks really cool in the dark!
 

 

[Mediahound]

I like them too although have heard the GE/Jan 5670 tubes are like $10 tubes and you can get an adapter on ebay for like $1...

 

[tbish]

  I like them too although have heard the GE/Jan 5670 tubes are like $10 tubes and you can get an adapter on ebay for like $1...

 
 
Oh my god, you're right... Still, I refuse to have buyer's remorse because these sound so good.
https://www.tubedepot.com/products/5670w-2c51w
 
http://www.ebay.com/itm/1piece-Gold-plated-5670-6N3-2C51-TOP-TO-ECC88-6922-6N2-tube-converter-adapter-/191860745369?hash=item2cabcaa499:g:3pgAAOSwKfVXJciG

 

[Rowethren]

I like them too although have heard the GE/Jan 5670 tubes are like $10 tubes and you can get an adapter on ebay for like $1...

Oh my god, you're right... Still, I refuse to have buyer's remorse because these sound so good.
https://www.tubedepot.com/products/5670w-2c51w

http://www.ebay.com/itm/1piece-Gold-plated-5670-6N3-2C51-TOP-TO-ECC88-6922-6N2-tube-converter-adapter-/191860745369?hash=item2cabcaa499:g:3pgAAOSwKfVXJciG

The adapter used by IFI looks way nicer than that eBay one though and I would rather have one designed and implemented by a known company that has warranty support. Supposedly the IFI adapter has circuitry within it that lowers noise, I can't confirm if it makes a difference over the other adapters but it nice to know they did something extra with it. Also you are paying for them to test all the tubes and sort them into matched pairs which is a pain to do yourself.

On a different note I was thinking these tubes were brighter but wasn't sure if it was my imagination or not, thanks for confirming I am not going mad! They are particularly sparkly.