slider313 Posted July 1, 2009 Posted July 1, 2009 The handwired, point to point Ampeg J20 is being discontinued and blown out at the stupid price of $299. The online website lists none in stock, but if you call your local store they may have one or can locate one at the next nearest store. Made in .........ready...............Vietnam but has very good reviews. May need a speaker change but these were selling for $799 just a few months back. JTILYK
slider313 Posted July 1, 2009 Author Posted July 1, 2009 It's a 20 watt all tube guitar amp with tremolo. One 5AR4 rectifier, two 6V6 power tubes and three 12ax7 preamp tubes. No reverb but very "60's" sounding.
tulk1 Posted July 1, 2009 Posted July 1, 2009 Very classic 60s, for sure. Would love to have one for the amp stable. Still full price every place else I looked. Great deal if you can find one at the SA blowout price.
Spectrum13 Posted July 2, 2009 Posted July 2, 2009 One coming my way tomorrow! Slidder... Would like to know if you plan to retube with NOS and how it compairs to your 63. Ampeg lover myself but is the new productions the same thing? Great price.
slider313 Posted July 2, 2009 Author Posted July 2, 2009 Spectrum13, Yes, I will use NOS 12ax7's and the New Tung Sol 6V6GT's. From what I've read, the circuit is close to the Fender Brown Deluxe model 6G3 and will sound nothing like my '63 Super Echo Twin. I sometimes use a 12at7 in place of the 12ax7 phase inverter for a bit more clean headroom.
Spectrum13 Posted July 2, 2009 Posted July 2, 2009 Slider what type of 12AX7's? After 44 years one of my RCA grey plate went cottontop and cracked so I'm looking to get a few different AX's to try out. I get nothing but clean headroom on my 7591 equiped Rocket but yesterday I switched out the remaining good RCA into my Swart and looked at the plates on that new JJ 12AX7 which came stock (just went bad too) and they look like crap. So, I'm tube shopping.
slider313 Posted July 2, 2009 Author Posted July 2, 2009 I'll try a few different ones to see which sound best. I have some GE,RCA,Sylvania,Westinghouse,Mullard,Telefunken and Amperex. Those old Rockets with the 7591's were meant to be clean. I had a '65 Reverberocket with 7868's. I put a Celestion Vintage 30 in it and used a tube screamer for break-up and sustain.
Spectrum13 Posted July 2, 2009 Posted July 2, 2009 "I have some GE,RCA,Sylvania,Westinghouse,Mullard,Telefunken and Amperex." That's what I'm talking about... $300 amp and $500 for preamp tubes. Addicted to the glass and man what a rush!
Gitfiddler Posted July 2, 2009 Posted July 2, 2009 Inexpensive point to point little amps are always a hot topic! I'm partial to the US made Ampeg Reverb models and might pick one up later down the road. This one got my attention (not my money, however), on Fleabay... http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...=tab%3DWatching
TalismanRich Posted July 3, 2009 Posted July 3, 2009 The handwired, point to point Ampeg J20 is being discontinued and blown out at the stupid price of $299. The online website lists none in stock, but if you call your local store they may have one or can locate one at the next nearest store. Made in .........ready...............Vietnam but has very good reviews. May need a speaker change but these were selling for $799 just a few months back. JTILYK Talk about a bummer. Yesterday I passed a Sam Ash in Hendersonville TN. Didn't stop. I used to have an old Echo Jet EJ-12A. It added the reverb to my Univox amp. I think Dad paid about $30 for it. It was one of the 7591 based models, 18 watts, no reverb by itself. 12" speaker. You had two leads that you clipped on the speakers of your other amp, and it would run through the reverb unit on that channel. You could get a semi "stereo" sound with the 10ft or so of cable that let you spread out the two amps. But as a 13 yr old, I wouldn't have known anything other than if it was loud enough to drown out my brother's drumming!
golferwave Posted July 3, 2009 Posted July 3, 2009 I've got a made in USA Ampeg SJ-12T Superjet. A very cool and great sounding amp. When I bought this one new at my local music shop I thought these came with 6L6's. When I looked closer at mine after getting it home I was surprised to see that it was factory equipped with EL34's.
slider313 Posted July 3, 2009 Author Posted July 3, 2009 Just got mine yesterday and spent a couple of hours tweaking tubes and changing the speaker. Actually it's made in Korea. As for tubes, this baby is running the EH 6V6's hot at 30ma@400v+. I switched the rectifier to a 5R4 and installed a pair of new Tung Sols for 21ma@386v . Got rid of the SovTek 12ax7wa's in favor of a GE 5751 in V1 (a must!), Sylvania 12ax7 in V2 and an RCA 12ax7a in V3. As for the speaker, I have a Jensen Jet ceramic in it for now and while it sounds real good, it sounded soooooo much better when I crossed it over to the Weber reconed '65 C12N I have in my '61 Vibrolux. I'm not crazy about the Jensen Jet. While it's louder, it doesn't have the clarity and balance the reconed C12N has (Weber's 12F150B cone). Also, the solder tabs on these Italian Jensen's crack off easily when removing the speaker wires!! Sounds very close, tonewise, to my '61 Vibrolux with not as much clean headroom and slightly "boxey" due to the cabinet size. Overall a great buy for a point to point wired 20 watt combo.
tulk1 Posted July 5, 2009 Posted July 5, 2009 Slider, What would estimate you put into that amp, dollar wise, to get it to your liking? I know you had the mods sitting around. But if you had to source that stuff, it sounds like it could be rather ... costly. And was it all that bad stock?
slider313 Posted July 5, 2009 Author Posted July 5, 2009 Kenny, A used 12" ceramic Weber 12F150 should be about $60. NOS 5R4 rectifier is $12.50 NOS GE 5751 for V1 $20. That should have it running and sounding great for under $100. The EH power tubes are fine but you really need to change the rectifier to get them running cooler. I happen to have plenty of NOS preamp tubes to fool with but the critical one is V1 for a cleaner tone with slightly less output, which allows you to turn the amp up to it's sweet spot; 6-7 on the volume. Mike
tulk1 Posted July 6, 2009 Posted July 6, 2009 In that case, Mike, wowzers!! What a deal. Not as bad as it sounded. I've always liked those Ampegs. Sorry I missed out on that one. But then, not sure I need another amp ........... oh wait. Of course I do!!!
Paul P Posted July 6, 2009 Posted July 6, 2009 The EH power tubes are fine but you really need to change the rectifier to get them running cooler. Isn't this a matter of personal preference ? My understanding is that running output tubes hot will get you more clean/headroom/definition whereas running them cooler will give you more warmth/breakup. Deluxe Reverbs put out 22w don't they, so this one is running cooler than that. A 6v6 is rated at 12w dissipation and you dropped it to 8 ? I'd be a bit surprised if Ampeg sold their amp operating too hot, surely they tested the thing. So what didn't you like about their tone ? As for the speaker, I can certainly believe that a bigger, better speaker would make a huge difference. I'm only speculating based on what I've read, I only have one amp (and no time to fiddle with it) so am not in any position to experiment and compare, unlike yourself.
slider313 Posted July 6, 2009 Author Posted July 6, 2009 Isn't this a matter of personal preference ? My understanding is that running output tubes hot will get you more clean/headroom/definition whereas running them cooler will give you more warmth/breakup. Deluxe Reverbs put out 22w don't they, so this one is running cooler than that. A 6v6 is rated at 12w dissipation and you dropped it to 8 ? I'd be a bit surprised if Ampeg sold their amp operating too hot, surely they tested the thing. So what didn't you like about their tone ? As for the speaker, I can certainly believe that a bigger, better speaker would make a huge difference. The hotter you run a tube, the earlier it will break up. Running them cooler gives more clean headroom but you can't run them too cold or you will get crossover distortion. Most modern 6V6's, like Tung Sols, EH's and JJ's are equal to a 6V6GTA which is a 14 watt tube. Running them at 60-65% is better for tube life and gives a cleaner tone when the amp is being pushed, keeping it more focused and tighter. The tone wasn't terrible but I knew it could be greatly improved with a tube and speaker swap.
Paul P Posted July 6, 2009 Posted July 6, 2009 The hotter you run a tube, the earlier it will break up. Running them cooler gives more clean headroom but you can't run them too cold or you will get crossover distortion. Most modern 6V6's, like Tung Sols, EH's and JJ's are equal to a 6V6GTA which is a 14 watt tube. Running them at 60-65% is better for tube life and gives a cleaner tone when the amp is being pushed, keeping it more focused and tighter. The tone wasn't terrible but I knew it could be greatly improved with a tube and speaker swap. Thanks for the clarification, I'm probably confusing higher plate voltage and higher dissipation. I was basing my comment on Fender's evolution to higher and higher plate voltages which I understand was in search of louder clean tones. I realize that higher voltage doesn't necessarily mean hotter running, depending on how you bias, but I thought that went up as well.
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