Whole hog...hmmm...This is an inappropriate post...kidding...heh heh...note that a LOT of amps use 12at7s (thousand of Jolidas for example). I suggest that while figuring this out, you mount them on a display with tiny LEDs under them and use them as art, make a tube cellphone, have a surgeon install a tube socket in your head so you can wear one (chicks dig this), and generally keep your head down so people forget this post and your credibility, such as it is, returns. |
I would just keep them if you might buy another tube preamp in the future. How many tubes are you talking about?
What preamp was it that you had a problem with? Since the buzz Was coming from one channel, did you try swapping the tubes to the other channel and see if the buzz followed the tubes? It could have been a bad tube.
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I was in a similar situation a while back with 12AU7 tubes. I kept the pair I liked best (Sylvania 12au7WA) and sold the rest on ebay.
Glad I kept them as I recently built a Bottlehead Crack headphone amp which uses a 12AU7 tube. |
Since your system didn't benefit with tubes,you should return the tubes and go back to solid state. |
You are not going to get any high offers selling them here or on ebay since they are in the white boxes and come from unknown sources. It would make a difference if you had a tube tester and could quote the test results.
If you are able to return the tubes to venders, then you'll get some money for them.
What I have done in the past, is if the white box has a vender's logo and the tube measurements on it, I will say how many hours that the tube was used (low hours) and put it up for sale. Some brands of NOS tubes will get you offers. |
Thanks for the responses. Until three weeks ago, I hadn't seen a vacuum tube since I was a ham radio operator 30 years ago as a kid. So, learning from scratch. Consensus seems to be that I'm not likely to recoup my investment easily. There's a guy down the way who repairs tube gear, so I might pay him to run a tester on the tubes if I try to sell them. Some have test results provided.
@lostbears: It's a Dared SL-2000a, which I know several folks around here have owned--the reason I got it. I bought all the tubes the cool kids were using, including Brimar 5v4g, Brimar 4033s--the "blemished" white box with TubeMonger bases--plus TUngshram e80cc NIB that I haven't opened yet, as well as an RCA rectifier and Sylvania grey plate triple micas. Like everyone said a few years back, the preamp is good gear "with the right tubes." The soundstage enhancement it offered was much more noticeable on a traditional solid state amp than it was on my class D. In fact, the all-Brimar complement brought the AB amp so close to the Abletec/Tripath sound, only a bit better, that it put me on the fence about whether the investment and added system complexity was worthwhile for me. I like it, but don't really miss it, given my other equipment.
Frugality seldom wins out in my audio system, so I think we all can guess what I will end up doing. But I'll see if I'm still in the return window on the tubes that weren't ideal in my system, however. Thanks again for the feedback. |
Oh, and @Timrhu: certainly swapped the tubes. I think it may have been a loose tube socket, since that one rattled just a little bit when I tapped it. Or ungrounded wire, or wire touching the transformer. Seemed unlikely to be just a ground loop, being only in once channel regardless of outlet and with nothing plugged into the inputs.
I actually had asked for a replacement, not a refund (including 2-way shipping, which was nice), but now I have the choice to repurchase, wait for a used one to go up for sale here, or to call it an educational experience and move on. The freedom to decide is nice...except when it isn't:) I'd hate to rebuy and have that one buzz to--not good for either me or the seller. Anyway, input on that issue is welcome, but I feel like I got my thread question answered by the above posts. |
Note that there are very few vegetarian ham radio operators. |
Put them on Ebay and make millions. |
Save them they will be worth a fortune in 20 yrs or so. |
Don't take either of these suggestions the wrong way, but what I do is:
1) Use them as Christmas tree decorations. Honestly, tie a string around them, and hang them on the tree. They actually look pretty cool, particularly, the coke bottle output and rectifier tubes. But your 12AT7s will suffice
2) Give them away. The minuscule amount of money that will come back to you in a sale will prove of little consequence compared to the goodwill of sending them along to someone who could actually use and appreciate them |
Save them in case someone breaks in your house, you could start throwing 12AT7s at them, they might actually explode on impact. |
I also have a Dared 2000a that I swapped tubes on. The seller accidentally shipped them with Electroharmonix AX7s. I pointed this out to him and he generously sent a pair of "Made in Germany" orange globe Amperex AT7s. However, using the correct tube type still created too much gain in my system. So I used the AT7s to replace the AX7s in my Jolida JD1703 hybrid amp, hopefully lowering the gain there, and then put on the Dared two of the extra-tall Philips 7062 computer tubes, which are lower gain than AT7s. Happy with the results. Total price: $15.
If I can keep getting deals like that on Ebay, then I don't mind stashing the extras in a bag. I can't imagine selling tubes to recoup costs unless I can provide measurements - except maybe for the orange globes. |
@Super390: Wow, a real post! I guess I invited the jokes with the title of the thread...
Well, I can ultimately provide measurements, one way or another, and all but 4 of them are in original boxes. One of these years, I'll give it a shot, since the restocking fee for one order would have been the price of one of the tubes and most others couldn't be returned, as it turned out. I had looked at the insane price-rise in AT7s since 2010, and wondered if it was going to keep going up. People on this thread, who have much more experience, seem to be implying it has plateaued, at least in the nearish term. Not a big deal: I'll get something back. And, there's always the Crhistmas tree.
Your great deal on tubes sounds like what people were saying about 5695s in the Dared, another computer 12AT7 equivalent that obviously (from the prices) hasn't caught on yet. I read that these uber-expensive Tungsram e80cc were flip-flop logic tubes, too (sounds like political tubes!) so they might even sound the same. As my "experiment" with tubes, I figured the only way for me to really judge would be to get the ones that "everyone" had said they liked the best, and call it an educational expense. Total cost of a set of 3 tubes I was using at the last, though, was the same as yours ...only with a 0 at the end.
As you experienced, the Dared is too much gain. Largely for fun and curiosity, I bought it to put it in front of a Parasound Zamp v3, which has a sensitivity of .6V and my DAC puts out 2V! 9:00 syndrome and hard to gain stage (lower-gain tubes in a preamp won't do all that much to change this, I've read, even if they worked). Sounded fairly non-detrimental and noticeably tuby anyway, though, so still thinking about it. It was the only piece of gear my GF has actually ever noticed, sitting down to put her nose practically on the volume knob. "It's pretty!" she said, gazing into the glow. Definite first. I don't think she wanted me to return it, though she couldn't give a crap about the sound.
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put them on your dresser and glance at them every time you pass, it works for me. i also put some in a box in the garage, this is also a good approach. |
