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6S19P tubes instead of 7233 tubes.?

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Vingborg

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Joined 2013
#1
Hello Everyone 🙂

I am about to build and test the low mu preamp design of Mr. Pete Millet. I have made contact with him and he have helped me with some questions about using 7233 single triode tubes instead of 6AS7 double triode. (Thanks Pete 😉)
But it is actually a little hard for me to find the 7233 triode.!

Now - I know about the russian equivalent 6S19P or 6C19P.!
Still I don't have the knowledge to understand the datasheets for these tubes to find out if I just can plug in a russian 6S19P instead of the 7233 tube without any changes in the 7233 tube circuit.?
The only thing I can see and understand is the recommended resistance in grid leak circuit: 7233 = 1M and 6S19P = 0.5M

And maybe something about the pinout, but that is no problem for me🙂

Can you guys tell me something about this matter.? I will be very happy 🙂

Best regards
Henrik
 
#3
6s19p is not so different from half a 6AS7; maybe slightly higher ra and a little bit more linear? I presume you can understand the pinout on the Russian data sheet?

Edit: I just checked, the data sheet at "Frank's Electron Tube Pages" is in English.
 
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#4
First beware of the pinout differences. Plugging a 6S19P into a 7233 socket will cause a direct short across the heater supply which in my case caused the 6S19P to shatter!

Other than the pinout issue the tubes are relatively similar. In my cathode follower amp they both worked about the same.
 
#6
tubelab.com said:
First beware of the pinout differences. Plugging a 6S19P into a 7233 socket will cause a direct short across the heater supply which in my case caused the 6S19P to shatter!

Other than the pinout issue the tubes are relatively similar. In my cathode follower amp they both worked about the same.
Click to expand...

Hi, thanks for the answers..
Yes, yes I'm aware of the pinout differences 🙂 I haven't build the circuit yet, but when I do I will make sure to connect right 🙂
But "relatively similar".. Are there some changes that I'll have to think about by using 6S19P instead of 7233 in this low mu circuit? :

http://http://http://www.pmillett.com/images/lowmu_sch.PDF

Best regards
Henrik
 
#7
How is that? Looks like they have the same heater connections, but pins 8 and 9 are reversed.
Click to expand...

You are right. I don't remember the details, or exactly how the socket was wired, but somehow two of the multiple plate connections got across the 6.3 volt 10 amp heater winding of my power supply and the tube shattered.

I had breadboarded a cathode follower output stage that had a 9 pin socket and I tested the 6S19P, the 7233, the 6S4, the 12B4 triodes and some pentodes like the 6CW5 and some unmarked Bendix tubes. The 6S19P and the 7233 were the best performing tubes. The 7233 is about $10 each although I had several pulled from scrap HP test equipment, but I got a box full of 6S19P's from an Ebay seller in the Ukraine for $30.

I then swapped in an octal socket and tried the usual suspects, 7239, 6080, 6AS7, 6528, and several sweep tubes. The best performers were the 6528 and the 6LW6.
 
#9
Hi,

The best performers were the 6528 and the 6LW6.
Click to expand...

And you know why, don't you?

@Vingborg: designing isn't exactly easy, tube rolling is for those that can't design really.
True electrical equivalents are rare. Most so called equivalents work but that's where it ends.
IOW, look at the circuit and what might be wrong, no tube swap will solve a problem or bring sudden magic.

Cheers, 🙂

Edit: EC 360 anyone? Guess not............
 
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#10
Tubes 6s19p Ulyanovsk and Svetlana different not to mention 7233 GE and Mazda.
 

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#14
i run it at 60ma /60v cat. /240v an. the tube is quite robust and stable, made for voltage regulation and in terms of use for audio favoring higher currents and lower voltages. but of course the best is to do one's own listening tests and considering its price, the experiments are even more rational..
 
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#16
hi Henrik,

I just finished Pete's pre-amp, 2nd build. I have tried on 7236 and 6AS7 tubes, and like Pete's testing the 7236 had more gain. Also, I am working out how to deaden the chassis and transformer. I think the xfr (Edcor) has a buzz as soon as I turn it on, tested w/o tubes. Sorry, I do not have O-scope so i cannot isolate it.

My final round of tubes are EH EL34s in the CSS, Russian 6AS7 (6H13C) and a TAD 5u4G. I have tested 7931 and they worked out very well. i did try Russian 5u4G variants and they buzzed, which transferred to the chassis...I did buy JAN 6080 (inexpensive) and sounded as good as the Russian version - which I thought was funny as it was a JAN tube and less expensive than the Russian.

Are you in Europe? If so, I bought my 6AS7 tubes from Tube Amp Doctor in Worms. They ship pretty fast and the prices are ok, @ 12€/tube a bit more if you go with the SED version.

6as7 - Onlineshop Startseite Tube Amp Doctor Onlineshop

no affiliation with TAD, I've just used their services in the past and found them very good.

Right now I am listening through Pete's pre and love it. The first iteration of the build - awful. Never build something when you are coughing so hard its hard to see and have a fever as well. I'm surprised it turned on and I had lots of burns on my hands from the coughing...holding the iron and coughing is a really stupid idea.

./e
 
#18
Hello Folks🙂

Back from vacation..

fdegrove said:
Hi,

Best? ED8000 by TFK. No questions asked.

Shuts up everyone doesn't it?

Sorry, Henrik, couldn't resist.

😉
Click to expand...


Hey Frank, That's alright, always a pleasure when you join in🙂


fdegrove said:
Hi,



And you know why, don't you?

@Vingborg: designing isn't exactly easy, tube rolling is for those that can't design really.
True electrical equivalents are rare. Most so called equivalents work but that's where it ends.
IOW, look at the circuit and what might be wrong, no tube swap will solve a problem or bring sudden magic.

Cheers, 🙂

Edit: EC 360 anyone? Guess not............
Click to expand...

I don't believe in magic either 😉 At this moment I have received 4 pcs. JJ EL34 (very beautiful tube) and purchased 8 pcs. 6S19P-V from Russia..

I thank you all for your attention in this matter..

Best from Henrik🙂
 
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