[ford2]

Quote:

Originally Posted by Zai /img/forum/go_quote.gif Mnnh i thought the power tubes didn't affect SQ at all.

+1,far better to spend your money on the 5751's etc.

 

[sbulack]

Quote:

Originally Posted by ford2 /img/forum/go_quote.gif +1,far better to spend your money on the 5751's etc.

Have you tried the recommended GE Red Label 12B4A's in your Mapletree Ear+ HD amp and found them in your listening to not be worth what you paid for them? If so, what other particular 12B4A's are you comparing them to, as the basis for you assessment?

The Head-Fier recommending this particular 12B4A tube in the Mapletree is mrarroyo, who I have found to be a particularly careful listener, and able to communicate well what he hears.

So, I am interested in the basis for the advice offered which differs from his recommendation of this 12B4A tube over other NOS 12B4A tubes.

In my own tube-rolling with NOS 12B4A's in the Mapletree, I have tried Sylvania, GE (not Red Label), RCA and Marconi, and I have not detected enough of a difference among them to cause me to prefer any of them over any of the others. This is unlike my tube rolling trials with 5751 and 12AX7 tubes for the Mapletree, in which I hear nicely appreciable differences in the sound when using the different manufacturer and vintage tubes in this Mapletree socket. mrarroyo's recommendation of the GE Red Label, though, prevents me from concluding that the 12B4A does not affect the SQ. It could be that I have just not tried a 12B4A tube, yet, which makes a difference making it worth the effort to purchase a pair.

 

[MacedonianHero]

Quote:

Originally Posted by sbulack /img/forum/go_quote.gif With the Ear+ HD and the ALO-780, I found that a Tung Sol Double-Mica, Grey Plate 5751 synergizes especially well. I pretty much always keep a pair of NOS 12B4A's in the Mapletree. I haven't noticed nearly as much of an effect on the sound as the manufacturer of the 12B4A's varies - as I have with the manufacturer/model of the 5751/12AX7 tube. If you really like the sound from the ALO-780 and you'd like to stick witih it for awhile and find tubes which work really well with it, I think it might be worth your while and investment to check out a Tung Sol DMGP 5751. Is the Tung Sol tube that you already have one of those? There's a fair bit of pretty good discussion of tubes for the Ear+ HD in this thread. I think that it would be worth your while to skim the 500 posts in this thread to look for the blocks of posts in which tubes for this amp have been discussed, tips traded and sounds described. One good source of tubes is the FS forum here on Head-Fi. As folks sell off a favorite tube amp that they've "tubed up" with, after a time, they may also sell off their (sometimes really nice) tube collections if they can't use them in the new amps they've upgraded to.

I was surprised when I popped in my 12AX7 with my MAD Ear+HD amp too. I thought my Sylvania Gold Grey Plate Triple Micas were the ONLY tubes, but now I'm not so sure...the Tung Sol is a re-issue with gold plating and I am still shocked 3 days later just how good it sounds.

 

[SemiAudiophile]

Quote:

Originally Posted by MacedonianHero /img/forum/go_quote.gif I was surprised when I popped in my 12AX7 with my MAD Ear+HD amp too. I thought my Sylvania Gold Grey Plate Triple Micas were the ONLY tubes, but now I'm not so sure...the Tung Sol is a re-issue with gold plating and I am still shocked 3 days later just how good it sounds.

I also have been using a Tung Sol gold pin reissue. It's a really nice sounding tube and I gotta say it's one of my favorites so far along with the GE TMBP and Sylvania Gold Brand. I don't think it is quite refined as the latter, but very close. Its got a nice blend of air, smoothness, and detail (lots of it), with a nice tubey roundness sound to it. Highly recommend as they go for pretty cheap, I got mine for $20 shipped.

 

[ford2]

Quote:

Originally Posted by sbulack /img/forum/go_quote.gif Have you tried the recommended GE Red Label 12B4A's in your Mapletree Ear+ HD amp and found them in your listening to not be worth what you paid for them? If so, what other particular 12B4A's are you comparing them to, as the basis for you assessment? The Head-Fier recommending this particular 12B4A tube in the Mapletree is mrarroyo, who I have found to be a particularly careful listener, and able to communicate well what he hears. So, I am interested in the basis for the advice offered which differs from his recommendation of this 12B4A tube over other NOS 12B4A tubes. In my own tube-rolling with NOS 12B4A's in the Mapletree, I have tried Sylvania, GE (not Red Label), RCA and Marconi, and I have not detected enough of a difference among them to cause me to prefer any of them over any of the others. This is unlike my tube rolling trials with 5751 and 12AX7 tubes for the Mapletree, in which I hear nicely appreciable differences in the sound when using the different manufacturer and vintage tubes in this Mapletree socket. mrarroyo's recommendation of the GE Red Label, though, prevents me from concluding that the 12B4A does not affect the SQ. It could be that I have just not tried a 12B4A tube, yet, which makes a difference making it worth the effort to purchase a pair.

First off I did not say that there was NO difference between 12B4A's,I agreed with the previous poster from what I have read that there is little to be gained from rolling power valves in reference to this amp.
My understanding is that the big gains come from the 5751/12AX7's etc.
The point of my post was simply that it is best to spend the money on the big gains rather than chase gains that might not be apparant to some.

And for your information my EAR+ HD SE has Japanese Raytheon 12B4A's and Sovtek 5751.

 

[mrarroyo]

Quote:

Originally Posted by sbulack /img/forum/go_quote.gif Yes, you found his post that I was referring to in my previous post above. And, now that I've read it again, I recognize it. Yes, it was the GE red label 12B4A that he recommended because "they sound so good". I haven't yet tried that particular 12B4A. Being reminded of Miguel's recommendation of it, though, causes me to put it on my list of tubes-to-try (scheduled for sometime in the next few months when I'll likely have more of an audio budget to use to try things than I do right now).

I had both the GE grey plate 5751 and a pair of red labeled GE 12B4A tubes on my Mapletree and it sounded really great. I still have two pairs of matched tubes which I have kept since I have thought of getting another Mapletree by Dr. Lloyd. The red label tubes can be found in eBay and as I recall they were not expensive, I think I paid like $30 for the matched set plus S&H. Good luck.

 

[SemiAudiophile]

1 GE/National 12B4A 12B4-A tube - NOS New In Box - eBay (item 360229798544 end time Feb-25-10 19:12:18 PST)

I bought some NOS National 12B4A's off ebay a few days ago. They look identical to the red label GE's posted by mraroyo in terms of construction and were re-branded for National according to the seller. They made a noticeable improvement on my amp sounding a bit smoother and mellower. Though I'm not sure if it's because that they were new or that my previous RCA 12B4A's were old and worn out (they were stock and had them since day one). The new National's sure have a nice glow to them though. My amp looks almost new again.

I'm actually considered buying a backup pair just in case..as there are only 5 left.

 

[sbulack]

Quote:

Originally Posted by SemiAudiophile /img/forum/go_quote.gif 1 GE/National 12B4A 12B4-A tube - NOS New In Box - eBay (item 360229798544 end time Feb-25-10 19:12:18 PST) I bought some NOS National 12B4A's off ebay a few days ago. They look identical to the red label GE's posted by mraroyo in terms of construction and were re-branded for National according to the seller. They made a noticeable improvement on my amp sounding a bit smoother and mellower... I'm actually considered buying a backup pair just in case..as there are only 5 left.

There are probably 3 left now, I just placed an order for a pair of them.
The pair of 12B4A's I'm currently using are not pushing their use limit, and are in pretty good shape. When I get the pair of these, I'll roll them in and listen if I can hear any noticeable difference in the sound that using these 12B4A's makes.

Nice tip, also, about the Tung Sol reissue 12AX7. It reads like a nice-sounding tube for such a reasonable price. In a little while, I'll likely buy one and compare it to the Tung Sol 5751.

 

[stang]

I need a pair of these but am really, really broke

I have the Tung Sol 5751

Sounds awesome, my second fac. Fav is probably my triple mica black plate Sylvania, although it hisses =/

 

[Voodoochile]

In my opinion, it is fair to say that the power tubes have less impact on the overall presentation, but they still do influence the sound and performance of the amp, as does every component. Some more, some less, but it all matters.

Tubes are easy to swap out, thus an easy avenue to modify the particulars of an amp, not unlike swapping a socketed op-amp in a SS amp.

Also, you can modify the gain via component choice in the amp, but the preamp tube does also affect the gain of the amp notably.

 

[Parafeed]

Quote:

Originally Posted by Voodoochile /img/forum/go_quote.gif In my opinion, it is fair to say that the power tubes have less impact on the overall presentation, but they still do influence the sound and performance of the amp, as does every component. Some more, some less, but it all matters.

I hope this doesn't turn into another "I wish I'd kept quiet instead", posting on a subjective topic about an amp I don't own.....

In my experience, the comment above about power tubes having less impact on overall presentation will be doubly true in this case, by virtue of the fact that the EAR has a cathode follower output stage. That tends to "equalize" subtle differences even more so than "rolling" tubes in a plate loaded circuit.

Another thing to note is that because the driver tube is direct coupled to the cathode follower output, (ie. the driver plate voltage is the bias for the output tube), swapping different tubes into the driver socket will also cause the operating point of the output tube to shift, especially when switching between 5751 and 12AX7. So it's not necessarily just a driver tube change you're listening to, instead the combination of the driver tube change plus the output tube shift in operating point as a consequence of the driver tube change.

 

[snejk]

Quote:

Originally Posted by sbulack /img/forum/go_quote.gif There are probably 3 left now, I just placed an order for a pair of them.

There should be none left now

I'll try them against my Sylvania 12b4a's. I used RCA's previously but they started to develop a noise in one channel.

 

[sbulack]

Quote:

Originally Posted by snejk /img/forum/go_quote.gif There should be none left now I'll try them against my Sylvania 12b4a's. I used RCA's previously but they started to develop a noise in one channel.

I just checked and the sale of this item is closed, with a history of 7 sold - which accounts for the total available stock.

 

[Zai]

Oh great. Now to be sure i'll have to find a pair of Red Labeled GE 12B4As

 

[ford2]

Quote:

Originally Posted by Parafeed /img/forum/go_quote.gif I hope this doesn't turn into another "I wish I'd kept quiet instead", posting on a subjective topic about an amp I don't own..... In my experience, the comment above about power tubes having less impact on overall presentation will be doubly true in this case, by virtue of the fact that the EAR has a cathode follower output stage. That tends to "equalize" subtle differences even more so than "rolling" tubes in a plate loaded circuit. Another thing to note is that because the driver tube is direct coupled to the cathode follower output, (ie. the driver plate voltage is the bias for the output tube), swapping different tubes into the driver socket will also cause the operating point of the output tube to shift, especially when switching between 5751 and 12AX7. So it's not necessarily just a driver tube change you're listening to, instead the combination of the driver tube change plus the output tube shift in operating point as a consequence of the driver tube change.

How nice to read an informative post,thanks.