codhead

"His son offered to buy them but he won't allow rap to be played through his babies." Sounds like the son is well on his way to being disowned!

The Teac was very quiet at idle. No background hash with the music paused. I can best describe the sound as being similar to what you would experience with a very low-end CD player. Keep in mind that this was a head-to-head comparison of a $100 SS amp against a $9,000 tube amp. I'm probably a little jaded from what I'm used to, but I'd still have a hard time characterizing the Teac's sound as anything approaching smooth.

The 630mV is the spec for the SE-40. I'd suggest measuring what your amp is set to now, and using this as a baseline. If 3 or more tubes measure very closely, use that value to set the remaining tubes. This will most likely turn out to be something less than the recommended setting, as the bias voltage tends to drop as the tubes age. There's a Golden Tube user's group over at Yahoo, and someone there might know the recommended bias voltage. You could also try posting a free want ad on Audiogon for a copy of the SE-60 manual. I did this with my first SE-40, and someone sent me a copy within a few days.

Must be that new "electron scrubbing" technology.

I'd try to verify the SE-60 bias voltage, but the procedure should be the same. If you're missing the bias adapter, it's the exact same plug as a computer's hard drive power connector (which you can use to construct one). The ground is at one end of the connector, and the next 3 wires correspond to the bias pots for the 3 tubes of the respective channel. BIASING THE GOLDEN TUBE SE-40 AMPLIFIER 1) Set the amplifier on the work surface facing you 2) Remove the 2 screws from the left side 3) Stand the amp up on the left side (where you just removed screws) 4) Remove the 2 screws from the right side (now facing up) 5) Remove the 6 screws from the bottom cover 6) Remove the bottom cover ***WARNING*** VOLTAGES ARE PRESENT INSIDE THE AMPLIFIER CHASSIS THAT CAN CAUSE DEATH ON CONTACT. IF YOU HAVE ANY DOUBTS REGARDING YOUR ABILITY TO SERVICE ELECTRONIC EQUIPMENT, TAKE IT TO SOMEONE WHO DOES THIS FOR A LIVING. ALWAYS MAKE ADJUSTMENTS WITH A PLASTIC SCREWDRIVER OR ALIGNMENT TOOL DESIGNED FOR THIS PURPOSE. 7) Connect the power cord 8) Connect the bias adapter to the lower connector 9) Set your multimeter to DC volts 10) Connect the black meter lead to the red wire 11) Connect the red meter lead to the yellow wire 12) Turn on the amplifier 13) Wait 3 minutes 14) Adjust the rear pot for 630 mV (0.630) left increases, right decreases 15) Move the red meter lead to the black wire (next to the yellow wire) 16) Adjust the center pot for 630 mV 17) Move the red meter lead to the black wire (next to the red wire) 18) Adjust the front pot for 630 mV 19) Turn off the amplifier and allow it to cool 20) Connect the bias adapter to the upper connector 21) Repeat steps 10-19 It may be necessary to repeat this procedure several times before the bias readings are all in spec. Do not exceed 640 mV. Do not set bias over 630 mV, as input power fluctuations will cause the bias voltage to slightly increase.

Contact Jeff Glowacki at Sonic Craft (soniccraft.com). He's THE authority on Golden Tube mods. I had 5 SE-40's at one time, and yes, they are a NIGHTMARE to bias. Your SE-60 is essentially an SE-40 with an upgraded power supply to support EL34 tubes. If I remember correctly, the circuit board says SE-40/SE-60 on it (same part in both amps). Sonic Craft has some reliability mods (replaces under-spec'd diodes, upgrades the PS caps, and upgrades the cheap bias pots with 10-turn military grade parts). Their mods came in stages, and were also available as a kit, if you're proficient at soldering. Anyway, I'd give Jeff a try. He can probably answer any questions you have.

You sure that's not EL34?

Think I preferred the title "Crazy Poster" better!

No big deal to me. I just hope Shawn enjoys it. It's all sealed up, addressed, and ready to go. Man, an amp with a "brain". Pretty soon they'll start talking... "You're clipping me, Dave!"

Well, if that's the case, Shawn just got himself a pretty good deal!

Shawn, All yours! May you have better luck than I did (threetriodes@aol.com). Might be a day or two before I can get to the Post Office, depending on my work schedule - but I'll E-mail you when it ships.

Don't respond twice if your reply does not show up right away! Apparently there is a delay with the new software.

Dean, Nope, not me. This was my first Tripath attempt. In all fairness, the graininess may be the power supply. My scope bit the dust, and my new Tektronix won't be arriving until tomorrow - or I would have checked. I tried the polarity switch on my Theta DAC, and it did not seem to make any difference (good thinking!).

Curiosity got the best of me, so I ordered a Teac Tripath amp from Needle Doctor. I unhooked my Topaz, plugged in the Tripath, and... (insert expletive). Maybe $400 worth of mods will give one of these a fighting chance (I'm not going to find out), but out of the box it's just plain nasty. Not much bottom end, and more grain than a Kansas wheat field. I think this is the first component I've ever owned that lasted less than 15 minutes in my system. Anyone wish to take this abortion off my hands for $60 via PayPal (half of what I paid)? I'll throw in insured Parcel Post shipping, and the original receipt. It spent less than 30 minutes out of the box, and is like new in every way.

Will be interesting to see if any other Mac users have problems with Internet Explorer. I just loaded Firefox, and it seems to work fine with the new forum software. IE has serious speed problems (on both of my computers), but only with the Klipsch forums.

Thanks guys. I'm using IE 5.2 on a Mac, and this site is like using a dialup connection vs. DSL. I'll download Firefox and see if that helps. If it's not the server, my browser must not like the new forum software.

It would seem that the new forum software may have exceeded the processing capabilities of the server.

Try a pair of these. Beautiful construction, transparent sound, and 10dB is enough attenuation to tame all but the worst mismatches. Go to audiogon.com, and do a search on "Rothwell" to find a dealer.

---------------- On 8/20/2005 8:32:49 PM BS Button wrote: That puppy look good, real good. Can't wait to get mine... ---------------- Let's hope you have better luck with shipping than I did! I thought about purchasing a new ST-70 II a few years ago. I remember the ad saying that the black chassis - like your amp - was an upgraded part over the earlier chrome model. Apparently the chrome chassis was pretty thin (like the original ST-70) and was easily damaged in shipping. Looks like you got the good one.

Here's another. *** Link fixed to start on page 1 of the review ***

Right here.

Well, I guess this kind of answers the question regarding how these sound. To me, the fascination with single drivers centers around 1) no crossovers in the signal path, and 2) a single point source of sound. Strangely enough, I think the best "soundstage" I've ever encountered with my system was playing my daughter's Ani DiFranco acoustic CD through my little Hasehiro MM151S horns. Not what I normally listen to, but the closest to "having the speakers disappear" that I've encountered. I'm sure the open baffles would sound great, if they are reinforced with those bass bins in the picture - and maybe a pair of T90A's on top. But to me, this all seems to defeat the perceived advantages of what attracted me to single drivers in the first place (but it certainly allows for a wider variety of music - which just may be what I've been looking for). Think I'm going to try an experiment tonight. I'll hook my 211 amp directly to the CD variable out and to just the woofers on my Chorus I's. I'll run the DAC output to my preamp, driving my Abbys with the 300B amps, and the T90A tweeters with my 2A3. The 2A3 has it's own attenuator, and I have some inline Rothwell attenuators I can put on the 300B if I'm not getting enough top end. It'll probably image very poorly, but I'm just too curious at this point not to give it a try. Might have to sacrifice an extension cord (for speaker cable) to get it all up and running, but that's a cheap price to pay.

---------------- On 8/20/2005 1:40:25 PM jt1stcav wrote: ...who actually rebuilt this particular ST-70, and from NOS parts or parts from an existing amp? Whoever did this remarkable update on this venerable Dynaco sure knows his way around this amp's design/construction. ---------------- It's from a guy named Chris Miller in Mariposa, CA. He does business under the name "Amplitube". It's all newly manufactured parts. The first one had original Dynaco output transformers. After FedEx dropped it, he built me another one from scratch - everything is new on this one. You can do a search on FedEx for my previous thread where the last one got damaged. Here is the original eBay listing, if you want to read about his amps. If anyone wants to contact Chris about an amp, his E-mail is amplitube@sti.net (he also sells these as kits).

I'd pick the "cheap crap" older ones, if I had a choice. If metal horns are prone to ringing, the thick ones would be better.

Here's Rev. 2 of the amp I purchased from Amplitube, FedEx having destroyed the first. It's a new ST-70, built on Scott's late-model Dynaco replacement chassis - and it's a real beauty. The amp is all new construction, and is built with almost all American made parts. Keep this in mind if you're contemplating an inexpensive new tube amp. Made here, assembled here, and new amp reliability - for around 600 bucks. Why go Chinese? It really does an outstanding job driving my '76 Heresys. As much as I like the Moth s2A3 I normally run in the bedroom, I have to admit that the little Dynaco has some conjones if you push it beyond 2A3 listening levels. While the mids may not be as refined as the little SET, it certainly has a way with classic rock that makes it a joy to listen to.