Cary SLP-05

pitdogg2

Good thing I don't drink or I'd be road tripping 😜

pitdogg2

Toolfan66 wrote: »

I would like to try a good set of 6922/6DJ8's, but a lot of them have sky rocketed in cost like the PQ's

I've tried this factory for a 6ak5, for Russian tube they were excellent. Cheap enough to try and an American seller so you're not getting cast off Russian junk. The Russians were all about quantity and not quality. There were however several factories that did make Superior Russian tubes this is one of them. Only certain factories were tasked with making the tubes that went into their ICBM'S or military so their quality control was much better.

https://www.ebay.com/itm/124098439815?


https://www.ebay.com/itm/325433360245?

GlennDog

Do you 2 gurus agree with this ... it’s a snap from Tube World

pitdogg2

What's the question Glen, the list or whether 12bh7 can be substituted for 12au7?

pitdogg2

I will tell you a very under rated 12au7/12au7a is the Westinghouse black ladder plater 12au7. Very good sonics, good bass and midrange and highs that are very good. i have many pairs.

GlennDog

pitdogg2 wrote: »

What's the question Glenn, the list or whether 12bh7 can be substituted for 12au7?

The list, mainly. I’m looking for good quality tubes at a fair price . . . Guess I’m in the wrong hobby!

Folks like Brent Jesse and Andy at Vintage Tube Services are great, but you sure pay for it

The chart below helps a bit. Read the last sentence under “Recommended use”

GlennDog

pitdogg2 wrote: »

I will tell you a very under rated 12au7/12au7a is the Westinghouse black ladder plater 12au7. Very good sonics, good bass and midrange and highs that are very good. I have many pairs for sale.

Fixed it for ya!

By chance, if you do . . . PM me 😉

heiney9

pitdogg2 wrote: »

I will tell you a very under rated 12au7/12au7a is the Westinghouse black ladder plater 12au7. Very good sonics, good bass and midrange and highs that are very good. i have many pairs.

I agree!!

The problem is you need to know the plate color (shade) and construction as there can be many tubes with a Westinghouse label that are not the tube described above. And many tubes with other labels that are the above tube.

Hint: Many of the earlier tubes made for use in organ amplifiers are a good source for the Westinghouse manufactured tube. A plus is all organ tubes are screened for ultra low noise. Westinghouse only manufactured their own tubes for a short time early on. Definitely a sleeper and a mostly unknown tube.

337 is the manufacture code for Westinghouse. Sometimes this is silk screened on the actual tube, usually in Yellow, but I've seen Orange as well. Look at Conn organ tubes, but you have to look for clues which I've provided the link for. The 3 gray dots are a big key that it is a genuine Westinghouse tube.

https://tubemaze.info/westinghouse-12au7-carbon-plates/

I used to have a large stash, but I sold off all but 3 pairs which I'm keeping.

As far as the Tube World chart, it's pretty general. I would never group a Mullard and Telefunken tube together as he did. He did mention a few date specific tubes, but take a Mullard from the 50's and
compare it to a Mullard manufactured in the late 60's, early 70's and they aren't the same tube.

Happy Hunting

H9

heiney9

I experimented with the 12Bh7 briefly and was not impressed. Granted it was a couple of the recommended brands but not a long demo each time.

Just my .02c

H9

pitdogg2

I know the 6bl7 is a good substitute for 6sn7 in some circuits, and from that list that is all. I'm also thinking that 12bh7 has different pin out than 12au7.

@heiney9
As far as the Tube World chart, it's pretty general. I would never group a Mullard and Telefunken tube together as he did. He did mention a few date specific tubes, but take a Mullard from the 50's and
compare it to a Mullard manufactured in the late 60's, early 70's and they aren't the same tube.

This^^^^^

RCA did make some tubes for Westinghouse and the structures/color are different. The Westinghouse black black plate is a dull dark graphite/carbon like color and not shiny like other black plates of that era.

Lol just looked at the link, I agree with the link and learned all that by myself 😉.

I will tell you a full suit of Westinghouse 12au and 12ax in my preamp was my super happy ear medication before I had to break down my rig. I'm so looking forward to that sublime listening when I get my rig set back up. I'll start out with the Westinghouse set up to acquaint myself with it before moving on to the tubes I've bought after the disassembly. Well recorded stuff was just soo 3d and floated out in front of you, it gave me chills ..aaaa lot

I've also bought a ton of tubes from the tube maze guy off ebay. He's legit and at times we have worked a deal on price if I was buying multiple sets.

@GlennDog if you want some decent sellers I've dealt with on ebay hit me up by pm I'll pass them along. I scan their stuff all the time and they have had most excellent stuff come through. One of them now if I put tubes in my watch list she'll start sending me offers and she'll provide a counter offer button, we usually meet in the middle. Sometimes however she will be frank and just say "I've gave you the best I can do" not once have I been disappointed. I do find it humorous that my two best sellers are tube queens and super knowledgeable about their stuff.

GlennDog

Thanks guys. It’s appreciated 👍

Ivan, I would like the leads. I’ll try to PM you later today

Thanks again!

pitdogg2

Some good reading here.

https://www.head-fi.org/threads/the-6sn7-identification-guide.209782/

Go down a few pages and read Philips Pope. You may be able to find the same tubes under another label

heiney9

I posted a link to a pair of Holland made 6SN7's w/Valvo label. If it were me I'd ask how he knows they are Holland made as Valvo did produce a 6SL7 in Hamburg for a very short time. One could reason they may have also produced a 6SN7 at the same time.

The Valvo 6SL7's I have are in original boxes that look the same as the link with a 1957 date. But the plates are silverish and curved w/ bottom D getter.

H9

Toolfan66

Here is a eBay link for a Zalytron brand Philips Holland NOS Pair, these look identical to my Popes, same code r93

https://www.ebay.com/itm/155193361605?epid=22018325635&hash=item24223ec4c5:g:pcAAAOSwXANjPQnM&amdata=enc:AQAHAAAAoEYDtwcFgjSVVMQpZbzCIFZDhLqsOPB+1yxHsf2u7QRLXyIvAeQXoDZbmuJw9rF7keI3ZF9W48Oi1uGaRhWeNFD7Pmf/F1se/Hp3N6P4dCUx1QVGKQoEoklwof+o8s8bpP3GPewBUGihWEwQWwHqu1uSYK6fn8KPk8UdTgNb48T5C7NoOqKSfs3LdAK46tC+yGEh5VMocWF+hpTmNuwzrZY=|tkp:Bk9SR8jw86mXYQ

Toolfan66

All eight of mine have the same date code L1F ( not sure what date it is LOL) Guessing June of 61 ?

rebelsoul

I just bought some white label 7308 pq amperex
1962 with shield gold pin . Paid $500

rebelsoul

That was 4 of them

pitdogg2

I believe the L denotes the Mazda tube plant Bruxelles, Belgium. 1 would mean 1961 or 51 more than likely it's 1961, F would be June.
My best educated guess.

Mike Reeter

Toolfan66 wrote: »

All eight of mine have the same date code L1F ( not sure what date it is LOL) Guessing June of 61 ?

I inquired about an Octet of Popes that a seller had along with an older SLP-05 for sale on US Audiomart recently. He said “the Popes were sold but the pre was still available”.

Now I know where they ended up, you lucky sob🤣

Happy for you👍

heiney9

Usually a Heerlen Holland made tube has the right triangle as the plant manufacture mark. Other plants in the Netherlands manufactured tubes as well, like Eindhoven, etc.

The top line of code is indicates tube type. r9 = 6SN7. The third digit indicates the change code or change number. In the case of the above "3" means it's been changed atleast 2 times. Meaning slight to very slight modification were made to the construction of the tube which gives it a new "change" number with each change.

Second line of code indicated place and time of manufacture. Time could be day of week or week of month. The first letter or symbol or number indicated the place of manufacture. In this case "L" according to my tube charts is M.B.L.E Bruxelles Mazda. "1F", with "1" being most likely 1961 and "F" being the month June.

Based on the codes these are made in Belgium by Mazda. Many times Mazda are French tubes. I did a quick Google of "Bruxelles" and it kept coming back to Brussels Belgium.

Pope does not and never has made their own tubes, they source tubes from everywhere and put their own stenciled label on.

So perhaps the Pope 6SN7 tube everyone seems to like is Made in Brussels Belgium. So it is very helpful to know what the codes are for the exact tube you are looking for.

H9

heiney9

pitdogg2 wrote: »

I believe the L denotes the Mazda tube plant Bruxelles, Belgium. 1 would mean 1961 or 51 more than likely it's 1961, F would be June.
My best educated guess.

Right on the $$$, I didn't see your much shortened version of my rambling post until I was done composing.....lol

H9

Toolfan66

I never had the feeling Pope made their own tubes after talking to Ivan about them, + Philip Holland would always seem to come up when you tried to find anything about them, there really isn’t a lot of info about Pope tubes in general..

So my date guess on my tubes was correct, and those ZALYTRON Tubes I posted above would in fact be the same tubes as well, just different date codes.

heiney9

Yes, that is correct.

pitdogg2

heiney9 wrote: »

pitdogg2 wrote: »

I believe the L denotes the Mazda tube plant Bruxelles, Belgium. 1 would mean 1961 or 51 more than likely it's 1961, F would be June.
My best educated guess.

Right on the $$$, I didn't see your much shortened version of my rambling post until I was done composing.....lol

H9

I threw a sharp object at a spinning wheel ... I got lucky 😉😜

Thanks Brock, finding this info is not real easy. What I did find was Philips never made the tubes and Pope was for export only. Mazda is definitely the maker.
Mazda made great tubes. They are not cheap or plentiful, but they are very desirable.
The shiney chrome plate 12au7 with the Siemens or Sonotube brand may have also been made by Mazda from my research.

As always you da man!

jbreezy5

L1F = Late one Friday.

heiney9

pitdogg2 wrote: »

heiney9 wrote: »

pitdogg2 wrote: »

I believe the L denotes the Mazda tube plant Bruxelles, Belgium. 1 would mean 1961 or 51 more than likely it's 1961, F would be June.
My best educated guess.

Right on the $$$, I didn't see your much shortened version of my rambling post until I was done composing.....lol

H9

I threw a sharp object at a spinning wheel ... I got lucky 😉😜

Thanks Brock, finding this info is not real easy. What I did find was Philips never made the tubes and Pope was for export only. Mazda is definitely the maker.
Mazda made great tubes. They are not cheap or plentiful, but they are very desirable.
The shiney chrome plate 12au7 with the Siemens or Sonotube brand may have also been made by Mazda from my research.

As always you da man!

One thing is for sure there are no absolutes when dealing with tube origins. Pope brand was for export, but I (have) and seen Pope branded 6x4 (EZ90) rectifier with Mullard Blackburn codes. Construction is 100% Mullard.

I will say that's interesting you found the nickel ladder plates that always have Siemens codes are manufactured by Mazda. Tube codes usually don't lie. If Siemens didn't manufacture the nickel plated ladder style ECC82, then it would have had a Mazda code not Siemens. It's my understanding the codes are etched before the silk screen labels.

I have both style of Mazda ECC82's and they look completely different. They aren't ladder style plates The plates are pinched in the middle. The rarer version has holes in the pinched portion. The other version has a rectangular cut out in the pinched part. The plate tabs are different too.

Style 1


Style 2


Style 3 (3 mica)


Some Mazda CIFTE or Mazda BELVU and those are mostly manufactured in France.

The only chrome plate Mazda tube I have is the ECC 83, I believe it's French


Rarer version is the one I have
Can't find a good photo



I am not necessarily saying you are incorrect as even I can learn something new and know I don't know everything. But I study construction and tube codes which gives a correct identification no matter what is silk screened on the tube for a brand. Of all the Mazda ECC82's I've run acrossed in person or photos I haven't seen construction that looks like the Siemens Chrome plate. Even the RT branded tubes from France that have ladder plates are different.

H9

H9

heiney9

I will say pinpointing definitive information about tubes that 40-60+ years old is hard to do and takes a lot of serious research to corroborate the general consensus. I was down the rabbit hole very deep, but I haven't been for years now, so I go by memory or a few notes I have or the tubes I physically have.

I had to remember the 5-7 obscure websites I always used as they weren't even saved in my favorites on this computer. That was a task in itself. I quit tubes cold turkey because it was starting to become an addiction. It's good to be back a short ways down the rabbit hole. I was even cruising EBAY, but I stopped. I really don't have to have anything. I have 95% of everything out there for 12A*7 and variants, 6x4 rectifier, 6L6GTC, 6V6GT, 6SL7

I just looked and I have a quad of the Siemens chrome plate ECC82. I have quads and more of anything I will ever listen to.

Happy Hunting

H9

pitdogg2

heiney9 wrote: »

One thing is for sure there are no absolutes when dealing with tube origins. Pope brand was for export, but I (have) and seen Pope branded 6x4 (EZ90) rectifier with Mullard Blackburn codes. Construction is 100% Mullard.

I will say that's interesting you found the nickel ladder plates that always have Siemens codes are manufactured by Mazda. Tube codes usually don't lie. If Siemens didn't manufacture the nickel plated ladder style ECC82, then it would have had a Mazda code not Siemens. It's my understanding the codes are etched before the silk screen labels.

I have both style of Mazda ECC82's and they look completely different. They aren't ladder style plates The plates are pinched in the middle. The rarer version has holes in the pinched portion. The other version has a rectangular cut out in the pinched part. The plate tabs are different too.



Some Mazda CIFTE or Mazda BELVU and those are mostly manufactured in France.

The only chrome plate Mazda tube I have is the ECC 83, I believe it's French

I am not necessarily saying you are incorrect as even I can learn something new and know I don't know everything. But I study construction and tube codes which gives a correct identification no matter what is silk screened on the tube for a brand. Of all the Mazda ECC82's I've run acrossed in person or photos I haven't seen construction that looks like the Siemens Chrome plate. Even the RT branded tubes from France that have ladder plates are different.

H9

H9

There are no etchings on the tube, just barely there silk screening. The pair came with one Siemens box and one Sonotube box. I never found good pictures, what I found was forum threads about the nickel plates and the consensus on the two threads was Mazda may have been the only company making them.

To add to confusion, I've also seen barely there Tungsram silk and mold fold marks we also know as another well known maker.

Same plates Mazda box looks like a Mullard box ect. Could be Mullard or Brimar, BVA was usually Brimar.


Fold marks and right tube looks like Tungsram silk. Has made in England silk. Fold marks in glass usually Mullard, Amperex? Hole in tube plate usually Mullard soo 🤷🏼‍♂️
We both chase or tail for knowledge and 60,70 plus years later its an educated guess at best.
So yes we are both still learning and most that know for sure have likely passed on.

So yes there is always something 😉

heiney9

All my ECC82 short ladder chrome plate tubes with double post halo getter's have Siemens-Halske tube codes etched in the glass. I just don't see incorrect etched codes being something that was common. I don't really see any known Mazda manufactured tubes that have similar construction. All the well known tube guru sellers pretty much list it as a Siemens made tube.

But, we can never know 100% for sure. I don't really use them as they seem a bit too bright for me, but I may roll them again to revisit my impressions....lol. I don't currently use any of the Mazda tubes either, but I haven't really given them a proper evaluation.

H9

pitdogg2

heiney9 wrote: »

All my ECC82 short ladder chrome plate tubes with double post halo getter's have Siemens-Halske tube codes etched in the glass. I just don't see incorrect etched codes being something that was common. I don't really see any known Mazda manufactured tubes that have similar construction. All the well known tube guru sellers pretty much list it as a Siemens made tube.

But, we can never know 100% for sure. I don't really use them as they seem a bit too bright for me, but I may roll them again to revisit my impressions....lol. I don't currently use any of the Mazda tubes either, but I haven't really given them a proper evaluation.

H9

I will double check, I seen nothing etched into the glass on first or second pass. I'll be honest, I've not been able to use them yet and I bought them because they were a cool plate I didn't have. Whoever made them I in the grand scheme of things I'm not losing sleep over. It's always nice to know for sure. It's part of the chase😄

These do not have a double post I'm aware of.