[gprro]

Thinking of picking up a couple. Local for $20 each, nos/nib. Good deal, good tube? Kind of new to tubes. Seller also has some nos ge 12at7's i'll pick up too as driver tubes

These would be going in a modded Jolida JD1000 in place of newer EH 12ax7's. The mods added some more detail, but border on pushing the upper mids a little hot or forward. Trying to get a little body and fullness back. Using SED El34's also.

[kehut]

Thinking of picking up a couple. Local for $20 each, nos/nib. Good deal, good tube? Kind of new to tubes. Seller also has some nos ge 12at7's i'll pick up too as driver tubes

These would be going in a modded Jolida JD1000 in place of newer EH 12ax7's. The mods added some more detail, but border on pushing the upper mids a little hot or forward. Trying to get a little body and fullness back. Using SED El34's also.

Yes..if they test well enough..GREAT deal on a GREAT tube! One of the best. Is this the 5751 or 12AX7? I'd go with the 5751..even though it only provides about 1/2 the gain..they sound excellent. FWIW...I used mine in a Jolida JD-100 cd player. The other tube I liked was the Raytheon Black plate 3x mica 5751 with Windmill getter. Fabulous tubes.

[gprro]

Yeah, the 5751's. I just emailed the seller about testing and maybe even matching. What should I look for in testing?

[pbrstreetgang]

Good tubes, I require testing on all NOS tubes unless they are selling for like 5 bucks

[kehut]

The obvious things would be no shorts, no gas leakage, Transconductance (Gm) readings that are closely matched say within 5% if poss. As far as actual readings / numbers go..that depends on which tester used. I am not sure of what a 5751 should test as NOS..( i forgot as its been quite a while) someone can perhaps help out...

But, I know these tubes ( if they are genuine 5 star GE as advertised) usually run anywhere from $90.00 -over $100 used and better than $150+ and up per pair, depending on if they are perfect print, have the orig. boxes and such. $20 each almost sounds too good to be true

Ken

[Jon L]

But, I know these tubes ( if they are genuine 5 star GE as advertised) usually run anywhere from $90.00 -over $100 used and better than $150+ and up per pair,

Not really.  GE 5 star BP TP are very plentiful and one can easily find them for $50-60/pair. 

The $150/pair is more in the realm of Sylvania triple mica black plates, which are great tubes. 

BTW, if one wants to pull back the upper mids a bit while adding richness, RCA BP TM may be a better choice, though these are going up in price also.

[gprro]

thanks for the info. The seller is going to "test the triodes" on his tube tester to see where they stand. I'll pick them up tomorrow and post a couple pics. If I don't like the way they sound I'll put them up for sale or trade.

[kehut]

But, I know these tubes ( if they are genuine 5 star GE as advertised) usually run anywhere from $90.00 -over $100 used and better than $150+ and up per pair,

Not really.  GE 5 star BP TP are very plentiful and one can easily find them for $50-60/pair. 

The $150/pair is more in the realm of Sylvania triple mica black plates, which are great tubes. 

BTW, if one wants to pull back the upper mids a bit while adding richness, RCA BP TM may be a better choice, though these are going up in price also.

You may be right about the Sylvania's. Perhaps im thinking the GE 5 star in another type....anyway. at $20/ ea...not a bad deal for a very decent tube.

[anthony a.]

i tried close to 30 different tube sets when i owned the jolida 100 cdp.  it was modded stage 2, but i can't remember which company.  in any case, the best tubes i found to be were the sylvania golds 5751, raytheon windmill getters, and bugle boy 12ax7.  the ge 5751 were okay, but these tubes simply smoked everything else in comparison.  that player was one of my favorites, expecially for its modest price.

[markC]

The GE's are decent, and for that money, (if they test well), it's a good deal IMO. They are 70% of the gain of 12ax7's by the way, not 50%. Sylvania 3 mica blackplate sounded better, to me, in my Jolida JD100, but best I tried were Brimar 12ax7's, (the British military type in the "cigar rolls"). They are nice and smooth with nothing standing out, yet still portrayed nice high end. This is in my system of course.
I've since moved on to a separate DAC that uses 6DJ8's and equivalent, but I've still got plenty of Sylvania, GE, Brimar and Raytheon 5751's; Just in case.

[djbnh]

Thinking of picking up a couple. Local for $20 each, nos/nib. Good deal, good tube? Kind of new to tubes. Seller also has some nos ge 12at7's i'll pick up too as driver tubes

These would be going in a modded Jolida JD1000 in place of newer EH 12ax7's. The mods added some more detail, but border on pushing the upper mids a little hot or forward. Trying to get a little body and fullness back. Using SED El34's also.

Tried the above mentioned tubes in my JD-100 and they were very disappointing, wicked poor tubes to my ears. Finally ended up with some NOS Sylvania 5751 tmb Gold Plates that smoked most everything else. I note I used some GE NOS JG 5751 triple mica blackplates that were far superior to the 5 Star tubes, just weren't at the same level as the Sylvania, yet still a very nice tube. YMMV.

[Jon L]

I used some GE NOS JG 5751 triple mica blackplates that were far superior to the 5 Star tubes, just weren't at the same level as the Sylvania, yet still a very nice tube. YMMV.

Hmm.  It's hard for me to believe the GE JG 5751 TM BP were "far superior" to 5 star in any system, but as usual YMMV.  To my ears the JG version (1952) sounds a bit smoother and richer which makes it sound a wee bit less detailed subjectively.  If one digs the JG sound, the rare KenRad 12AX7 D getter does it more better 

[gprro]

I got em. Think it was a good deal too  .

The 5751's measured 128/128 and 136/136 so close to 5% matching I guess. Will this matter in a pre amp section? The 12at7wc measure 126/128 and 130/128. I still don't really know what these numbers mean 

Here's some pics






I'll see how they sound soon. If I don't like them anyone wana trade something?

[gprro]

After looking at some pics I think these are gray plates? They are GL-5751's. Some places are calling them black plate, others gray. They look black.

edit: tube world had me confused, they posted a pic next to a gray plate for comparison. I though they were showing only gray plate. They're black I guess.

[markC]

They certainly look black to me. As for the numbers, you need to know the value that the tube tester lists as a "new tube" reading for that tube.

[gprro]

The guy said they tested new. I found some more numbers after opening the bottom of the box. Writing looks as old as the tube. Numbers are 1060/1100 and 1120/1160.

I should mention too that they are getting used in the pre amp section of a jd 1000a integrated amp. The 12at's will be the drivers. Swapping out newer EH's for these. CD player is a stock samsung hd841. Needs full modding if I keep it. Thats were some of the upper mid forward/ lightness in the midbass might be coming from. I think I'll end up with a modded light dac60 though. More tubes to play with in that also.

[tonyptony]

I got em. Think it was a good deal too  .

The 5751's measured 128/128 and 136/136 so close to 5% matching I guess. Will this matter in a pre amp section? The 12at7wc measure 126/128 and 130/128. I still don't really know what these numbers mean 

What brand and model of tube tester did he use?

[gprro]

  I'll have to email and ask.

[SET Man]

The guy said they tested new. I found some more numbers after opening the bottom of the box. Writing looks as old as the tube. Numbers are 1060/1100 and 1120/1160.

Hey!

    The number that you've found there look like test result in "micromhos" Or "Gm" scale. Likely they are from tester like Hickok. Well, since the writing is very old and if those tube have been use since than the actual reading could be less now.

   I have a Hickok 6000. This one give list of value of what  "average new" tube should measure at, strangely no minimum value. But I do have a list of TV-7 tester of which give the "minimum" value of tube so I know when it is time to toss the tube.

   

I got em. Think it was a good deal too  .

The 5751's measured 128/128 and 136/136 so close to 5% matching I guess. Will this matter in a pre amp section? The 12at7wc measure 126/128 and 130/128. I still don't really know what these numbers mean 

     Yes, you do need to find out what tester the seller use. And what is the value of "new" tube of this type should be and what is the minimum value.

Take care,
Buddy