[gerado]

I can swear there is a big difference  between the LF and Soraya.
Do a blind test and Im sure I will pick the right amp 50% of the time

But seriously I thought the new amp was cleaner in sound presentation, though was not aware the LF can be specked up to the Soraya

And Hugh, under that banner should be a classic quote from the movie Kenny , a small Oz movie about portaloos and divorce.
"cut out the middleman, find someone you hate and buy them a house"

[raptor]

Neil,

I have no doubt you are right - my terminology was production changes - perhaps significant differences is more correct and yes, it's not just the nameplate.  Perhaps if I get mine fully upgraded as well there will be few if any LF2's in existance and Soraya will become the correct terminology.  In any case it is Hugh's call but I do think he wanted the name change to reflect the differences between production items and kits.

Lyn perhaps you are right and we should keep them unchanged. They may turn out to be a collector's item

I've changed my avatar; the new one is of the Soraya that Hugh was fine tuning to take to Denver when I visited him.

[lonewolfny42]

I've changed my avatar; the new one is of the Soraya that Hugh was fine tuning to take to Denver when I visited him.

And....it sounded very good in Denver....

[gerado]

Now we are way off topic

there is a range of numbers of equivalent tubes mentioned before in this post that have been tried in the GK

How do you know what tube is an equivalent replacement to try- when I have looked up tube data sites  on the web , there is only 3-4  6DJ8 equivalents listed and not G38B or 7308/E188CC

I just ended up with a huge load of tubes (600-700) and I dont recognise a lot of them though keen to make them glow in the GK if they were compatible

[lonewolfny42]

http://www.audioasylum.com/audio/faq/joes-tubes.html#6DJ8

http://www.audioasylum.com/audio/faq/joes-tubes.html#6DJ8-2

[gerado]

Ahhh thanks lonewolfny

should of remembered those links

[kyrill]

Now we are way off topic

there is a range of numbers of equivalent tubes mentioned before in this post that have been tried in the GK

How do you know what tube is an equivalent replacement to try- when I have looked up tube data sites  on the web , there is only 3-4  6DJ8 equivalents listed and not G38B or 7308/E188CC

I just ended up with a huge load of tubes (600-700) and I dont recognise a lot of them though keen to make them glow in the GK if they were compatible

For what I understand from the web most parties (90%) do not consider the 6ES8 as a substitute of the popular 6dj8 family. Their line of reasoning is the 6ES8 was never designed for audio circuits but t is a variable-mu tube intended as a cascode-type amplifier in TV tuners. This variable mu can cause problems in audio amps.

Hugh however has designed the GK-1 around this "variable mu" tube.
So although the 6ES8 may not be a Plug and Play substitute for the ECC188/E88CC family, the other way around maybe a different story. So the 6DJ8 and substitutes all the way to 7308 and cca tubes with their "fixed mu properties are substitutes for the 6ES8. The Gk-1 does not need the variable mu i think, if i read the  posts:

Hugh's comment"..
You can use the 6DJ8, however it will deliver a slightly less engaging sound.  Like any tube circuit, you can change the presentation by tube rolling with different types and brands, but only within the limitations set by the principal electrical parameters of the 6ES8."

Darren (DSK) underlines how beautiful his 7308 is >>the stock tube and actually "proofs" how compatible the 6DJ8 (ECC189) is to the 6ES8.
Also Ginger states: " I substituted some modern production JJ Tesla ECC88 (6DJ8) for theECC189 (6ES8) on the work bench and very carefully measure all operating voltages and currents.

The ECC88 (6DJ8) goes in without any requirement to change any circuitry or component values."

the official substitutes of the 6ES8 are?
6ES6  (http://www.g3ynh.info/Racal/M1ebv/RA17Leq.html)
6DT8
CV5331
CV2298
ECC189

An advantage of the much less popular 6ES8 that Hugh has made to be so musical, is it is much less expensiveness
So i will try the ECC189 lines too

[kyrill]

" The reputation of Siemens & Amperexes precedes them and they are frequent targets for counterfeiters. How do you know if a tube in question is the genuine article? Well, fortunately there are a few basic checks you can perform to differentiate true Siemens & Amperexes from relabeled Sylvanias and Tungsrams.

First, check the top of the tube in question. Siemens & Amperexes always have small ridges in the surface of the glass on top of the tube radiating outward from the nipple. These tubes will have 4 ridges, though sometimes only two of them are easily visible. The concept here is to look down on the top of the tube. The 2 or 4 ridges should divide the circular silver top of the tube in half or into quarters. No ridges? No genuine article pass on it.

Second, check the metal shield above the upper mica spacer. On Siemens & Amperexes it�s circular with two raised rectangular sections on opposite edges of the shield. On most fakes that shield is a perfectly flat disc.

Third, about 90% of Siemens tubes have a 1 or 2 digit number molded into the inside bottom of the tube glass centered between the pins. It can sometimes be very hard to see but it�s usually there. Remember, not all Siemens have it, but if your tube passes test one & two and has the number(s), it's a Siemens.

Fourth, familiarize yourself with the shape of the glass bottle on your stock Sovteks. Note that the top is smooth (no ridges) and rather rounded and the tube is short & large in diameter these traits are common to all Russian tubes in this family. Siemens & Amperexes are only about 80 to 85% of the diameter of the Russian versions and tend to have squarer shoulders on top rather than the rounded top of the Sovtek. You should be able to spot the difference between a Russian and a genuine NOS tube just by the shape & diameter of the glass pretty easily. One warning though Sovteks often (always?) have a number molded into the bottom of the tube between the pins like a Siemens, so know all the checks and don�t depend on just one to verify the tubes origins.

Fifth, if it�s a Siemens or Amperex 6922 or 7308 it will always have gold pins. So will some cheap counterfeits, so gold is no guarantee. But if they aren�t gold its not a Siemens or Amperex, so pass on it." http://www.audioasylum.com/audio/faq/joes-tubes.html#6es8
 
Kyrill

[jules]

Great assemblage of research Kyrill 

Given the apparent variability of tubes and the need to see what you buy, online purchase seems very risky. This makes tube purchase tricky though Hugh has always made the point that the tubes aren't as critical in the GK-1 as in some other apps.

Still, given the recent discussions and success with platinum caps, I'm wondering if the most promising path to customizing the sound of an amp is through "cap rolling" rather than tube rolling. Jupiter Beeswax output cap anyone?

jules

[andyr]

I dont care how good it is ,Im not going to think about it ,Im not going to do it!

Yesyes, you are Theo ... you can't help yourself!!   

Regards,

Andy

[kyrill]

Kyrill,

There is an article on interpreting those numbers that I've seen somewhere.  If I find it I'll post but someone else is sure to know off the top of their head.
 
.....
 

ok i found a bewildering me comprehensive explanations of codes that is practically of no help to me..miss examples
                           
http://www.audiotubes.com/mullcode.htm
Telefunken:
http://www.audiotubes.com/teledate.htm

example found, one Example code: I63 / B4B2:
                               


I6 – 12AX7 / ECC83
3 – Revision Number 3
B – Blackburn Works, UK
4 – Date Code , Last Digit of the Production Year (1974)
B – Date Code, B=February
2 – Date Code, Second Week of February

[kyrill]

original message moved to general audio forum

[AKSA]

Kyrill,

Many thanks, this is interesting, if cryptic, information.

Appreciated,

Hugh

[kyrill]

old news but i back it up now from own experiences  thx DSK

replacing Hughs original tubes 6es8 with siemens gold pin 7308 is a major upgrade

much more 3D much bigger soundstage and more depth. A bit more transparency ( i think more transparency is beyond the little "bad" speaker . all sounds are slightly articulated or should i say detailed,  sometimes to the spectacular
With certain bad cd's and FM sometimes the instruments when real left or right, were glued to the box, bigger than the box, but in the same place.
With the orignal 6es8 this happens all the time, transparent, clear but at the place of the box ( only with R or L only information) Telling me something of these speakers,,,ah well these are my kitchen speakers.
with the next type of tubes in same context the sound came completely loose from the speakerbox in all situations

with high pitch tones cymbals flute  and so on the effect is eerie as the recording properties start to disappear completely and i wake up from my trance because my brain warns me something is suddenly  entering the room. All above descriptions happened with my cheapo Eltac bookshelve kitchen speakers and AKSA amps. NO DEQX No high end drivers from Focal

However i required a next type of tubes: a pair of the famous Siemens CCA brand new as it needed 100+hrs to be burned in and to bloom. Same effect as the 7308 but much more "normal" more relaxed no slight articulation and with the Eltac a loss as it needed this bit extra definition support.
the depth however is deeper, more air and the instruments more 3d by themselves. strange effect to hear a single guitar note that sounds 3D by itself, not its place on the performance stage but as if you can hear the 3d of the snare micro 3d effects
their effect is that of an expensive component upgrade

I can only dream how these super tubes will sound in my real setup.

i have ordered NOS/NIB Siemens ECC189/6es8


So i am quite curious how they will compare

[kyrill]

Hi mate,

I'm just using the standard tubes and very happy with them but I have read through the following thread a few times and wondered - http://www.audiocircle.com/index.php?topic=7379.0 in case you haven't seen it.

To be perfectly honest, since adding the platinum caps, I've rather stopped wondering as I am so pleased with the sonics.  Hope you don't get me started again.

hi Lyn you owe it to yourself to do tube rolling the effects equals or even surpass the platinum upgrade
Helas it does make sense. A cap is very p a s s i v e
imagine the influence of an a c t i v e component

[MikeC]

I have a pair of gold pin Siemens E88CC's, delivered in a box identical to what Kyrills photo shows. I managed to get a pair from a South African valve dealer who managed to obtain a few from a local stash of several hundred before they were all shipped off to the USA to be sold for obscene profits.

My GK-1 sounds so good with them in that they never came out. The same dealer had 2 pairs of Siemens CCa's , but would not sell them; he is keeping them for himself. If I could find a pair of these at a price less than the cost of the GK-1, I might be tempted.

Mike

[LM]

Darn it Kyrill,

Your previous post was hard enough to ignore with its pretty picture beckoning me to also buy similar lovely components.  Now you go and lay down a direct challenge.

Actually, the only reason I am able to temporarily avoid (notice, I can't totally ignore) such a challenge is that I am pretty busy at the moment with little time for research or chasing down a tube buy; and I doubt I would buy without trying.  Now if Hugh or someone else handy had them commercially available on their shelf at some half reasonable price and I could roll a few through on a trial basis before commiting, little doubt I would be a goner.

[gerado]

The siemens do sound attractive to try
so far I keep going back to the original tubes however
I thought I found something better- Telefunken NOS E188CC but direct comparison left no doubt. The Teles certainly sound better on my AR pre amp but not the GK. Various other cheaper tubes just sound terrible

who stocks the siemens ? And the obvious question- are they ridiculous cost?

[raptor]

The siemens do sound attractive to try
so far I keep going back to the original tubes however
I thought I found something better- Telefunken NOS E188CC but direct comparison left no doubt. The Teles certainly sound better on my AR pre amp but not the GK. Various other cheaper tubes just sound terrible

who stocks the siemens ? And the obvious question- are they ridiculous cost?

When I was looking I came across this site in the USA. http://www.audiotubes.com/6dj8.htm

I thought that the prices were too high but managed to buy a cheaper used pair through a forum in Oz.

[gerado]

Just checked the prices

thats truly silly money territory