[TrollDragon]

Definitely something not quite right about those, big red flag. Little money lost and lesson learned.

 

[barbazz]

Portuguese poet José Carlos Ary dos Santos once said "Christmas is when a man wants". Who am I to disagree?

 

[triod750]

Portuguese poet José Carlos Ary dos Santos once said "Christmas is when a man wants". Who am I to disagree?

Enjoy!

 

[TrollDragon]

Portuguese poet José Carlos Ary dos Santos once said "Christmas is when a man wants". Who am I to disagree?

Very nice! Tube rolling is a lot of fun and quite inexpensive with the LD.

 

[barbazz]

Very nice! Tube rolling is a lot of fun and quite inexpensive with the LD.

Very nice!!!

Here's my rolling box:

Still waiting for 4 opamps and 5 tubes, including one MUSES8920 that hopefully will not catch fire and a pair of the much praised EI Yugo 6HM5s.

 

[barbazz]

My rolling sessions are never dull.

No, this time there was no smoky opamp involved but there was some drama.

Was rolling CSF Miniatron 6AM6S (boring...) and Philco Star Light 6CB6A (not bad, but still far from the Voskhods), both 7-pin pentodes that use LD's EF92 settings. Call it a day and reverted to my beloved Soviets. And... no sound!!!

Panic again! I was sure to have taken off both jumpers. Double checked and they were in the bag. Did the Voskhods said goodbye?? Grabbed a pair of GE 6AK5 that also use EF95 settings and nothing. Something was wrong. Opened the lid to check if the opamp was well connected or something and what did I found?

I didn't took off the jumpers, I only took off the PLASTIC and the metal part was still doing contact... This never happened to me before and, just in case, with the help of a drop of glue will not happen again.

Looking forward for tomorrow's rolling session. Will I burn the house? Records will start spinning backwards? Stay tuned

 

[TrollDragon]

Been there done that.

 

[Riversalt]

Does anyone know this RSD brand?
I need a pair Ecc82/12au7 and I found these RSD Ecc82, but I don't know anything about it, I have a xduoo ta 22.

 

[barbazz]

RSD was (or is, since BTB Elektronik still holds the brandname) a German brand based in Frankfurt. They didn't produce tubes but, instead, source them from Eastern Europe. RFT in East Germany and Tungsram in Hungary were the major suppliers. Most probably those ECC82 were made by RFT.

 

[triod750]

RSD was (or is, since BTB Elektronik still holds the brandname) a German brand based in Frankfurt. They didn't produce tubes but, instead, source them from Eastern Europe. RFT in East Germany and Tungsram in Hungary were the major suppliers. Most probably those ECC82 were made by RFT.

And, if so, they might have been made using Telefunken equipment...

 

[califmike33]

Can somebody give me a couple of good choices for the power tubes on this amp? Too much reading too many different tubes just looking for a couple good suggestions?

 

[Cognomen]

Two purported National Union 6AR5 Little Dot III drivers arrived "cloaked" with only 5239 printed on them (photos attached). Disconcerted, I wondered if they possibly were not 6AR5's. The internals looked exactly like a duck (i.e like a 6AR5), especially so when I noticed pin 7 was not connected inside to anything, just like a 6AR5. I wondered if they might be 4 volt 6AR5 variants or something else. After digging a lot I found a 5239 European tube, but it looked very different and has a different pinout anyhow. I took a chance and plugged the National Unions in and electrocuted them. They quacked like ducks and did not misbehave or carry on more than that or overheat. If you happen to have raised ducks, you know how they can do that! Perhaps 5239 is a production date, and they are oddly labeled 6AR5's. 5239 appears on the tube box in the photo below as well as on other tube boxes for different National Union tube species on Ebay. The second tube's box has 5152 printed on it instead of 5239. The box also has 6AR5 on it and only 5239 on the tube making it a cosmetic match for the 1st tube.. So far I have enjoyed listening casually. It will probably take some time before I have a subjective impression whether they sound like run-of-the-mill LDIII driver tubes to me or better. They seem to amplify less than the typical driver tube, perhaps not so suitable for low-z cans, but it's not an issue here because I mostly listen to almost nearfield 92 db sensitivity ADS speakers at low volume that I pulled out of my neighbor's garbage to see how they would sound. Better than Good! I power them with a capacitor-coupled Mitsubishi DA-A30 (Diatone) power amp with its input levels cranked down to fleawatt. At full throttle it is probably capable of delivering 200 watt peaks and quickly cooking my speakers unless it cooks itself first due to loss of coolant (freon?) in its pipe cooling system. When I want to be even quieter I leash myself to 250-z Beyer Amirons powered by the 2nd to highest gain level on the little duckling.

 

[barbazz]

Two purported National Union 6AR5 Little Dot III drivers arrived "cloaked" with only 5239 printed on them (photos attached). Disconcerted, I wondered if they possibly were not 6AR5's. The internals looked exactly like a duck (i.e like a 6AR5), especially so when I noticed pin 7 was not connected inside to anything, just like a 6AR5. I wondered if they might be 4 volt 6AR5 variants or something else. After digging a lot I found a 5239 European tube, but it looked very different and has a different pinout anyhow. I took a chance and plugged the National Unions in and electrocuted them. They quacked like ducks and did not misbehave or carry on more than that or overheat. If you happen to have raised ducks, you know how they can do that! Perhaps 5239 is a production date, and they are oddly labeled 6AR5's. 5239 appears on the tube box in the photo below as well as on other tube boxes for different National Union tube species on Ebay. The second tube's box has 5152 printed on it instead of 5239. The box also has 6AR5 on it and only 5239 on the tube making it a cosmetic match for the 1st tube.. So far I have enjoyed listening casually. It will probably take some time before I have a subjective impression whether they sound like run-of-the-mill LDIII driver tubes to me or better. They seem to amplify less than the typical driver tube, perhaps not so suitable for low-z cans, but it's not an issue here because I mostly listen to almost nearfield 92 db sensitivity ADS speakers at low volume that I pulled out of my neighbor's garbage to see how they would sound. Better than Good! I power them with a capacitor-coupled Mitsubishi DA-A30 (Diatone) power amp with its input levels cranked down to fleawatt. At full throttle it is probably capable of delivering 200 watt peaks and quickly cooking my speakers unless it cooks itself first due to loss of coolant (freon?) in its pipe cooling system. When I want to be even quieter I leash myself to 250-z Beyer Amirons powered by the 2nd to highest gain level on the little duckling.

I'm pretty sure that those references are connected with manufacturing lots. National Union production ceased by 1954 so, based on the first two digits, you probably have 1951/1952 manufactured tubes.

Glad they sound good. What setting are you using? EF95?

 

[Cognomen]

I'm pretty sure that those references are connected with manufacturing lots. National Union production ceased by 1954 so, based on the first two digits, you probably have 1951/1952 manufactured tubes.

Glad they sound good. What setting are you using? EF95?

EF95. EF 91/92 bridges pins 6 and 7. They should run just as well and sound the same in that mode because pin 7 is not connected to anything inside the tubes. The pins are a skosh thicker than my other 7 pin miniatures which makes them a little bit harder to socket.

 

[TrollDragon]

Can somebody give me a couple of good choices for the power tubes on this amp? Too much reading too many different tubes just looking for a couple good suggestions?

The first part of the table on page 585 shows output tubes that we can use, some need external power supplies and most need adapters. The eBay links in the table to the Powersocket adapters are long since dead, but there are other adapters available.
https://www.head-fi.org/threads/lit...e-rolling-guide.563884/page-585#post-11155053