LittleJoeSamson
118 posts
Nov 14, 2009
7:37 PM
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I know everyone has their faves, and every amp is going to sound different with various speaker configurations and mic's.
The different combo's are likely infinite.
The old line was that a harp player found a git rig that had been run thru the ground and the slingers couldn't get any more out of it. Then it was good for harp.
But now, with even beat up vintage units going for their weight in gold ( OK, maybe silver )...they're pricey for something that may have other age related problems: dry speaker cones, dry caps, scratchy pots....that all require extra $$$.
New units are readily available, but almost always come stock with "ice-pick-in-the-ears" Chinese trash or lifeless sovteks.
Any surprises here for inexpensive tube swaps?
I've found for drive tubes that many of the US made from the 60's are great: GE, RCA, Sylvania.
For the pre-amp tubes, I've switched out the 100 mu 12AX7's for lower gain 12AT7 variants ( 6201, 5965, 6211, 6829 ) that seem to sound best, for me. I am looking to experiment with 12AY7's to see how they sound, but they are somewhat pricey.
12AU7's have a nice tone, but at 17-19 mu, very little volume.
12AV7's just seem to have no depth.
I've tried a 12AZ7 in the V1, but was bright like 12AX7.
Popped it in the reverb slot and it sings.
Anyone here have other configurations?
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congaron
267 posts
Nov 16, 2009
12:08 PM
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I am about to order a 5751 for my preamp tube. I tried a bunch of 12ax7 variants and that was my favorite for gain before feedback in a small room. I'm using a valve junior, so that may be different since there's no tone control. I found i don't have any feedback issues in a real stage environment anyway, but the 5751 seems to give me a couple of tone options the 12ax7 didn't have..since I have no tone control. Frankly, nowdays, i use a pedal/modeler inline too, so the tone control is whatever i program in.....but I still want a 5751.
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Kingley
507 posts
Nov 16, 2009
12:38 PM
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I never tube lower than a 12AY7 these days, as I find that if you go to a 12AU7 it just cuts the tonal qualities of the amp too much and kills a lot of the liveliness.
A 12AY7 in V1 in my experience keeps the amp nice and lively and gives it a much fuller sound. Most people seem to believe that because you can turn the volume up much higher (between 8-10 is pretty common) with a 12AU7 in V1 that the amp is louder.
I think this simply isn't the case at all.
All the 12AU7 does in my opinion is cut the gain and volume right back which just means you have to turn it up to get the same effect you are getting at 3-5 with other tubes.
For me the only tube of choice in V1 is a 12AY7 for a good harp tone with most amps.
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Bluzdude46
276 posts
Nov 16, 2009
1:30 PM
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I'm with Kingley on the 12AY7 I have one in my Bassman LTd but I have 1 12AU7 and a 12AX7 in it too. For Single tube Pre Amp you are better off with good 12ax7's and inexpensive tube swap? Why are you going to spend hard earned money on a good Tube amp and try to save $10 on tubes???
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LittleJoeSamson
121 posts
Nov 16, 2009
1:42 PM
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Yes, I am anxiously awaiting delivery of a pair of 6072A/12AY7's to see how they sound.
The 6201/12AT7WA's were good, but the medium mu 5965's and 6211's produced the best sound with greatly improved microphonics ( i.e. none ).
It would seem that gain of in the 40-50% range is the sweet spot for voicing for harp.
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Delta Dirt
38 posts
Nov 16, 2009
3:21 PM
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I tried in vain to make my Fender Blues Jr. sound good to me. If anyone would like to buy my 5751 Sovtek, 12AY7 RCA, 12AT7 Mullard,and 5751 Jan Phillips for $40 there yours. Tried them all for 5 minutes tops.
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Delta Dirt
39 posts
Nov 16, 2009
3:30 PM
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Oh Yeah, got a mini meteor on the way. Dig City.
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Cisco
36 posts
Nov 16, 2009
5:18 PM
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I'll take those tubes for $40. Email me at cisco@email.arizona.edu. I can pay with Paypal or send you a check.
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LittleJoeSamson
123 posts
Nov 16, 2009
6:26 PM
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I let the amp warm up for at least 15 minutes before playing. Especially important when changing tubes.
Biasing should not be an issue with pre-amp tubes, but if the power tubes are changed it could be. I don't know whether the Blues Jr. is self-biasing or not, but it's generally a good idea to do so.
[That's a fair deal for those tubes, DD. Have fun with the mini-meteor.]
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mrdon46
17 posts
Nov 16, 2009
9:20 PM
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Another vote for 5751s--mu is 70, don't really notice any drop in useable volume from 12AX7s, but less feedback prone and richer sounding, IMO. My favorite preamp tube though is 6SL7 (octal), also 70 mu.
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harpnik
1 post
Nov 16, 2009
11:12 PM
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Question for Delta dirt,,What are the mini meteor,s going for price wise,? If you dont mind me asking.
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