DTB300
Well-known member
Anyone have any experience with these they would like to share???
http://www.upscaleaudio.com/product.asp?itemid=546&catid=40
http://www.upscaleaudio.com/product.asp?itemid=546&catid=40
12ax7m
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aliveatfive
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Haven't heard these yet. My experience with "off" brand tubes is that they are a crap shoot. It all depends on price. Try a couple (if the price is not exorbitant) and compare with a known quantity. My reference would be Telefunken, but they are rare and costly.
Dan, like Seth, I have not heard anyting about these as well. I assume you going to use them in your SP-16 ?? FWIW I 'rolled in' a pair of NOS GE 12AX7WA into my LS-16 prior to selling and was quite happy with the results, noise floor / microphonics were very low.
Like Seth said trying a pair won't break the bank, but if you do be sure to post your thoughts !!
Also , not to 'derail' your thread, but what's new on the Arcam front ?????
Like Seth said trying a pair won't break the bank, but if you do be sure to post your thoughts !!
Also , not to 'derail' your thread, but what's new on the Arcam front ?????
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eknuds01
Well-known member
Dan!
Where ya been, man? When's the next get-together at your house (I want more of that potato salad!)
Hope you are well.
Erik
Where ya been, man? When's the next get-together at your house (I want more of that potato salad!)
Hope you are well.
Erik
sebrof2000
Well-known member
Dan - I recently bought a set of the GT 12AX7s for my Jolida CDP from a local guitar shop, just for kicks. I won't be much help because I made other changes to my system so I never took note of the sound of the tubes specifically. I did remove them and put back the RCA 5751s that I bought to replace the original 12AX7s. I do prefer the 5751s over the 12AX7s that were in there.
I saw on Upscale that they have $15 5751s and $50 5751s. I'd personally go for the 5751s, whichever my budget would allow (in my case the $15).
Have you read Joe's Tube Lore? That's how I 1st found out about 5751s in place of 12AX7s.
Mike
I saw on Upscale that they have $15 5751s and $50 5751s. I'd personally go for the 5751s, whichever my budget would allow (in my case the $15).
Have you read Joe's Tube Lore? That's how I 1st found out about 5751s in place of 12AX7s.
Mike
Groove Tubes have been around for many years. They have been used in the music industry i.e. guitar amps as well as studio equipment industry for many years with positive results.
Like any change of tubes from the original design, as well as with cables, they will all have their own characteristics. I do not believe it will be a bad move in Dan's case. I think it will be different. Only Dan will be able to decide if he likes the new sound signature of the tubes. It is a win-win because if it not what he had hoped for, he can always put them on 'Gon or maybe return them. He always has the existing tubes to fall back on.
So go get em' Dan and enjoy!:music:
Jeff
Like any change of tubes from the original design, as well as with cables, they will all have their own characteristics. I do not believe it will be a bad move in Dan's case. I think it will be different. Only Dan will be able to decide if he likes the new sound signature of the tubes. It is a win-win because if it not what he had hoped for, he can always put them on 'Gon or maybe return them. He always has the existing tubes to fall back on.
So go get em' Dan and enjoy!:music:
Jeff
DTB300
Well-known member
I am used 1950 NOS 12AX7 RCA's in place of the stock EH's that ARC provides and liked the change. They are almost 1.5 years old now, but like any tube which changes over time, you really do not know what a new tube can give you in terms of sound improvement.
I have read good and bad about these tubes, but Upscale seems to have a good name with them in terms of selling tubes. So I guess we will see how they sound when they get here. Heck I paid under $100 with shipping for three of them, so no large investment if I do not like them. And if they have issues with longevity, I will keep the RCA's around as hot-spares in case.
In terms of the 5751's, I had read that, but just in case before I did that, I would check with ARC just to make sure I would not void any warranty.
Dan
I have read good and bad about these tubes, but Upscale seems to have a good name with them in terms of selling tubes. So I guess we will see how they sound when they get here. Heck I paid under $100 with shipping for three of them, so no large investment if I do not like them. And if they have issues with longevity, I will keep the RCA's around as hot-spares in case.
In terms of the 5751's, I had read that, but just in case before I did that, I would check with ARC just to make sure I would not void any warranty.
Dan
slowGEEZR
Well-known member
Dan, I just ordered them. Heck, for what they cost, I'll try some tube rolling!
DTB300
Well-known member
The 1950 RCA's "may" be referred to as that, but I am not sure. I bought mine from Vintage Tube Supply. Great guy to talk to about tubes. Vintage has some of the best prices around, but being a one-man show, it takes a bit of time from order to shipment which some might find too long (those with the instant gratification syndrome). But I would highly recommend them to people looking for tubes.
I saw that Upscale carried the new GT "Mullard" clone, so I thought I would give the tube and Upscale a shot. BTW, the same day I ordered the tubes they were shipped by Upscale.
Dan
Everything you need to know . . . .
. . . . . . . about 12AX7's and 5751's: http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html except where to find them and how much they'll cost you these days I like the 5751's better. Specifically the RCA 3-mica blackplates and (if you can find/afford them) the Sylvania 3-mica blackplates. I got my best tube deals on eBay, but you have to be quick and savvy. Otherwise buy them from a reputable dealer and pay 5X more.
. . . . . . . about 12AX7's and 5751's: http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html except where to find them and how much they'll cost you these days
I like the 5751's better. Specifically the RCA 3-mica blackplates and (if you can find/afford them) the Sylvania 3-mica blackplates. I got my best tube deals on eBay, but you have to be quick and savvy. Otherwise buy them from a reputable dealer and pay 5X more.
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DTB300
Well-known member
Some other info & comments on 5751 vs 12AX7's out there on the 'net
"Sometimes a 5751 can be used in lieu of a 12AX7. Some folks (guitar guys typically) that have gear that come equipped with 12AX7's will sub a 5751. They do this specifically because it colors the sound and changes the way the amp performs. They are looking for ways to "distort". This is a matter of taste as the 5751 is a lower gain tube than the 12AX7. If someone tells you to use a 5751 because they like it, make sure it's the same piece of gear. A lower gain tube can, depending on the circuit, operate perfectly. However, in some extreme cases, the lower gain can cause high distortion and in some cases not even work properly.
5751 tubes do not have a "sound" that is particular to that tube any more than 12AX7's have a "sound". It depends on who made the 5751 and when, the operating condition of the tube, and the circuit it's going into. Any other assumptions or statements about the merits of that tube are silly."
"Sometimes a 5751 can be used in lieu of a 12AX7. Some folks (guitar guys typically) that have gear that come equipped with 12AX7's will sub a 5751. They do this specifically because it colors the sound and changes the way the amp performs. They are looking for ways to "distort". This is a matter of taste as the 5751 is a lower gain tube than the 12AX7. If someone tells you to use a 5751 because they like it, make sure it's the same piece of gear. A lower gain tube can, depending on the circuit, operate perfectly. However, in some extreme cases, the lower gain can cause high distortion and in some cases not even work properly.
5751 tubes do not have a "sound" that is particular to that tube any more than 12AX7's have a "sound". It depends on who made the 5751 and when, the operating condition of the tube, and the circuit it's going into. Any other assumptions or statements about the merits of that tube are silly."
A little further on 5751's
The slight difference in gain between 12AX7's (100) and 5751's (70) is not even noticable in amp or preamp applications -- maybe a couple of degrees more on your volume control. And if you're using an ultra-low output moving coil (like 0.3 mV) you might want the little extra gain afforded by a regular 12AX7 (but you'd lose the ultraquietness of the 5751, which is also very important in tube phono preamps.)
Guitar players sometimes like to put 5751's in their guitar amps because some (most?) rock guitarists like "fuzz" -- a slightly distorted buzzing -- in their sound. They can get that sound earlier and with less overdriving if they use a 5751 -- that's all, it doesn't apply to audio.
5751's have two advantages in audio. First, they are "ruggedized" for militaty use. This means they usually have a third mica spacer just above the second one on top of the plates, just below the getter. This combined with extra support rods (usually copper) provides a rigid assembly that eliminates any microphonics (which is why they're also used exclusively in tube microphones.) The second attribute of 5751's (over 12AX7's) is that each of their two separate triode sections are perfectly matched (if they're not, someone is trying to sell you rejects!) This is important in audio because in some parts of the circuit, each channel is going through one side of a single tube, and in other places (amplifiers) each side of one tube is driving one of a matched pair of power tubes -- either way, you can see the need for matching inside the tube -- and where pairs of twin triode tubes are used, matching between tubes becomes important as well. This is not to say that one can't find matched 12AX7, AT7, AU7, etc. You can, but you have to sort through a lot more tubes to find them.
About plates: black plates and/or smooth plates are more desireable than gray plates and/or ribbed plates. And long plates (17 mm) are more desireable than short plates (10 mm). These are of course general statements. But let me give you an example: The 5751 du jour is the Sylvania Gold Brand 5751 with 3-micas, gold pins and ribbed gray plates (about $200+/pair) and they don't come with black plates. There is a military version of this tube that has plain pins (and for less money!) however some audiophiles prefer the sound of the Sylvania Gold Brand 3-mica, blackplate, and which only comes with regular pins. Why? Because along with the fact that black plates run cooler and last longer, important for audio (according to some), is that they produce a more detailed, open, airy sound due to the higher plate current achieved with black plates (you'll notice almost all power tubes use black plates, but that's mostly a heat dissipation thing.)
I have tried different brands among each group (5751's and 12AX7's) and I'm prepared to make some general comments which other people I've "rolled" tubes with have mostly confirmed. As always, there are exceptions :bowdown: but if you had a choice between two otherwise identical tubes:
1. Blackplates sound better than gray plates.
2. Smooth plates sound better than ribbed plates.
3. Long plates sound better than short plates
4. 3-micas sound better than 2-micas
5. Tails which shouldn't wag the dog: gold pins. Clean pins, yes!
Favorite 12AX7 brands (i.e. what each of them does, it does well and has no glaring inadequacies ):
Telefunken
Amperex (Holland) - comes in many brand names
Mullard (both regular and CV4004 military version)
RCA (blackplate and longplate only)
Favorite 5751 brands:
Sylvania black plate government contract (JHS, CAA, etc) gold labels
Sylvania Gold Brand black plate (plain pin)
Sylvania Gold Brand grey plate (gold pin)
Any Sylvania tubes should be: 3-mica only, green or gold labels OK, I prefer blackplates, but it's a matter of taste and equipment, and plain pins are just fine.
RCA (3-mica with blackplates only)
GE (3-mica with blackplates only)
Joe's Tube Lore has a few other thoughts/recommendations.
The slight difference in gain between 12AX7's (100) and 5751's (70) is not even noticable in amp or preamp applications -- maybe a couple of degrees more on your volume control. And if you're using an ultra-low output moving coil (like 0.3 mV) you might want the little extra gain afforded by a regular 12AX7 (but you'd lose the ultraquietness of the 5751, which is also very important in tube phono preamps.)
Guitar players sometimes like to put 5751's in their guitar amps because some (most?) rock guitarists like "fuzz" -- a slightly distorted buzzing -- in their sound. They can get that sound earlier and with less overdriving if they use a 5751 -- that's all, it doesn't apply to audio.
5751's have two advantages in audio. First, they are "ruggedized" for militaty use. This means they usually have a third mica spacer just above the second one on top of the plates, just below the getter. This combined with extra support rods (usually copper) provides a rigid assembly that eliminates any microphonics (which is why they're also used exclusively in tube microphones.) The second attribute of 5751's (over 12AX7's) is that each of their two separate triode sections are perfectly matched (if they're not, someone is trying to sell you rejects!) This is important in audio because in some parts of the circuit, each channel is going through one side of a single tube, and in other places (amplifiers) each side of one tube is driving one of a matched pair of power tubes -- either way, you can see the need for matching inside the tube -- and where pairs of twin triode tubes are used, matching between tubes becomes important as well. This is not to say that one can't find matched 12AX7, AT7, AU7, etc. You can, but you have to sort through a lot more tubes to find them.
About plates: black plates and/or smooth plates are more desireable than gray plates and/or ribbed plates. And long plates (17 mm) are more desireable than short plates (10 mm). These are of course general statements. But let me give you an example: The 5751 du jour is the Sylvania Gold Brand 5751 with 3-micas, gold pins and ribbed gray plates (about $200+/pair) and they don't come with black plates. There is a military version of this tube that has plain pins (and for less money!) however some audiophiles prefer the sound of the Sylvania Gold Brand 3-mica, blackplate, and which only comes with regular pins. Why? Because along with the fact that black plates run cooler and last longer, important for audio (according to some), is that they produce a more detailed, open, airy sound due to the higher plate current achieved with black plates (you'll notice almost all power tubes use black plates, but that's mostly a heat dissipation thing.)
I have tried different brands among each group (5751's and 12AX7's) and I'm prepared to make some general comments which other people I've "rolled" tubes with have mostly confirmed. As always, there are exceptions :bowdown: but if you had a choice between two otherwise identical tubes:
1. Blackplates sound better than gray plates.
2. Smooth plates sound better than ribbed plates.
3. Long plates sound better than short plates
4. 3-micas sound better than 2-micas
5. Tails which shouldn't wag the dog: gold pins. Clean pins, yes!
Favorite 12AX7 brands (i.e. what each of them does, it does well and has no glaring inadequacies
):Telefunken
Amperex (Holland) - comes in many brand names
Mullard (both regular and CV4004 military version)
RCA (blackplate and longplate only)
Favorite 5751 brands:
Sylvania black plate government contract (JHS, CAA, etc) gold labels
Sylvania Gold Brand black plate (plain pin)
Sylvania Gold Brand grey plate (gold pin)
Any Sylvania tubes should be: 3-mica only, green or gold labels OK, I prefer blackplates, but it's a matter of taste and equipment, and plain pins are just fine.
RCA (3-mica with blackplates only)
GE (3-mica with blackplates only)
Joe's Tube Lore has a few other thoughts/recommendations.
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Gents, interesting feedback, thanks ! As a side note to the 12ax7 discussion I have been thinking about a change in the tube output (12AU7,ECC82's) of my Cary 303/300 CD player, present tubes are a 'Phillips Heerlen' from Holland. I don't know if these are some of the Amperex (Holland) variants that Neil spoke of or not ??? A fellow on the Asylum did a comparison of 12AU7's on the Cary and felt the Siemans E82CC/12AU7 was superb, with Radiotechnique 12AU7 (circa 1956) a close second.
Anyone able to second his opinion ??
Anyone able to second his opinion ??
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DTB300
Well-known member
Out of your list, I like the RCA best, then the Tele's, then Amperex. The Amperex and the EH's from ARC are pretty equal to me. There are differences in each of these, as would be expected, but the RCA's just sounded right. I have yet to hear a real Mullard as they are usually too pricey to think about, hence the audition of the GT clones.Favorite 12AX7 brands (i.e. what each of them does, it does well and has no glaring inadequacies
Telefunken
Amperex (Holland) - comes in many brand names
Mullard (both regular and CV4004 military version)
RCA (blackplate and longplate only).
But all of this is moot depending on the quality of the tube auditioning, the components auditioning with, source used, room, etc. etc. What sounds good in one setup, may not sound good in another.
Dan
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DTB300
Well-known member
Just an opinion based on my setup and room. The list of what I like really means nothing other than its an opinionwith your ranking (notwithstanding your escape clause
and others should try and decide themselves.Twitch
There are almost too many Amperex (Heerlen, Holland) brandings to list. The two Amperex branded tubes are the Bugle Boy and the Orange Globe. But yes, Phillips is one. Also Hewlett/Packard, Eico, Dynaco, ITT, IEC, Mullard, and on and on. . . . . . .
There are almost too many Amperex (Heerlen, Holland) brandings to list. The two Amperex branded tubes are the Bugle Boy and the Orange Globe. But yes, Phillips is one. Also Hewlett/Packard, Eico, Dynaco, ITT, IEC, Mullard, and on and on. . . . . . .
I remember reading about sub'ing an ECC85 for the 12AU7,I think in the audio asylum some owners were stating its merits in your Cary player; although the ECC85 is difficult to find.
E.A.R PL509 amps (which I had at one time) used them in one of their driver stages.
You might even be able to sub a 5751 in there, I believe they are pretty close in MU output, naturally check with Cary before going outside the 12AU7 realm.
