[SemiAudiophile]

The sylvania gold brand triple mica black plates are really, really good (the one on the far left that Joe posted). I think Timbre Wolf and Joe sums it up pretty nicely:

Sylvania Gold Brand 5751 triple mica blackplate? Info please? - The Gear Page

http://www.audioasylum.com/scripts/d...s.html#12AX7-3

They do sound like the GE TMBP's but even better to my ears. And the GE TMBP's are one of my all time, all-around favorites. I think the GE TMBP's may be a tiny bit "sweeter" sounding. But the sylvania black plate is more refined, detailed, and presents a even more distinct soundscape. The black plate sylvania has much better control from top to bottom (especially in the highs) and sounds more neutral than it's gray plate sibling. Being a sylvania, i think it shares similar characteristics as it's gold brand gray plated brother. But the black plate version, to me, sound much more musically seductive, and have a very easy on the ears, pleasant sound. while the gold branded gray plate has too lush of a midrange for my taste and not as good control.

 

[AdamOBlivion]

What are the identifying marks on a GB? Is it the gold pins, or is that even a rarer GB model?
I was recently in the market for a 5751, specifically either a Raytheon 5751 Windmill Getter or a Sylvania 5751 GB/JHS triple mica black plate. I ended up snagging a Raytheon JRP 5751W1 Windmill Getter. I had owned, and loved, one in the past; I went with what I knew. I'd still love to try the triple mica when I have the spare cash.
This is for use in a guitar amplifier, btw. Just thought I'd throw that out there. I don't think I've ever had the pleasure of owning any HiFi amplifiers.

 

[jamato8]

I have found the Sylvania gold pin 5751 grey plate to be less noisy than the black plate. Sometimes you find them with normal pins but most of the time they have the gold plated steel pins. I always like the gold pin and still have NOS for when I need them. A good tube that hold up well. Often the JAN of whatever make, was the same tube as the civilian, just marked JAN as they were contracted for it. And sometimes a tougher tube was called for and then there was more mica etc. There were many variables. 
 
The GE 5 star is nice and is the command series. 

 

[hainss]

Hi, 
 
I am new to the world of tube. 
 
I need new tubes to replace the stock tube (12ax7 only marked China) of my Musical Paradise MP-P1 phono preamp. One of the tube make noise, and I got a good «hum».
After the purchase of my tube phono preamp to replace my Cambridge Audio 540, I got a really improvement in sound, more bass, more soundstage, better from the bottom to the hedge!
After that I decide to change my Planar 2 for a Rega - RP-8. Now, I can hear more details. My cartridge is not good enough, but I think I hear better the limit of my stock tube. Sometime, I feel that I hear to much high, not well balanced sound, and less body in the sound.
 
I decide to bought 5751 to replace my stock 12ax7. This is what I ordered:
http://www.ebay.ca/itm/131579459777?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT 
http://www.ebay.ca/itm/131579474293?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
 
someone know if the are legit? a good buy for the price?? 
seller have same model with lower life for less, but I decide to go with the strong. 
 
I dont see Sylvania gold... at a good price, do you think the GE will do the job? 
 
Tube is a strange world. 

 

[Skylab]

Yes, the black-plate triple mica GE 5751 is an excellent tube. Will sound much, much better than your Chinese 12AX7.

 

[hainss]

Well, I contacted Garry, the man who made my phono preamp, he said that I can put two 5751 in the front row and I will obtain a decrease of gain, but if I put two 5751 in the back row I'll have a decrease of sound quality. I don't know why the back row position is different, probably a different fonction. 
 
The Back row need 12ax7. 
 
The problem is I bought four 5751, now I don't know what to do. I want the best sound. I'll try with the four 5751... 
 
If I want a good matched pair of 12ax7, do you have good recommandation?

 

[jamato8]

  Well, I contacted Garry, the man who made my phono preamp, he said that I can put two 5751 in the front row and I will obtain a decrease of gain, but if I put two 5751 in the back row I'll have a decrease of sound quality. I don't know why the back row position is different, probably a different fonction. 
 
The Back row need 12ax7. 
 
The problem is I bought four 5751, now I don't know what to do. I want the best sound. I'll try with the four 5751... 
 
If I want a good matched pair of 12ax7, do you have good recommandation?

He probably based it on the voltage gain of the tube, which is going to be different with the 5751. It doesn't hurt to try. I was once told by a well respected tube preamp/amp manufacture that the 5751 would not sound as good but he was wrong. I also told him as an input tube I preferred the 6DJ8 type and he scoffed. later I saw that he changed the same preamp board to use the 6DJ8. You never know for sure until you try. 

 

[hainss]

how the back row and the front row of the preamp can do such a diffrence?

 

[jamato8]

how the back row and the front row of the preamp can do such a diffrence?

Back row and front row doesn't say anything as to where they are in the circuit or what they are doing. On one amp one might be the input tube and the other a cathode follower or a buffer. You would need a schematic. 

 

[jamato8]

 
Back row and front row doesn't say anything as to where they are in the circuit or what they are doing. On one amp one might be the input tube and the other a cathode follower or a buffer, a voltage gain tube and so on. You would need a schematic. 

 

[hainss]

If the position, front and back row, have two different fonctions, how 5751 can give a less quality sounding than a 12AX7. Less gain can do a problem depending of the fonction? If it's not a question of gain, how a different model of tube can do such a problem like a less quality sound?
 
Sorry for my english