I built the Dynaco ST70 in the 1970's. I learned to solder with that kit. I used the amp for 15-20 years (until tubes became unavailable) - it took about 30 seconds to turn on. I always thought it sounded better than more powerful solid state amps. I wanted to modify the half wave rectifier to full wave but never got the components.
Yeah, I did go through and create a parts list and posted it in the Tubelab forum, I was hoping someone would be able to give me a thumbs up but I may email it to George as well. I did get a comment that I was missing 2 items that weren’t in the list and that the list on the website wasn’t current (why not?).
I do have the board already so I may still go that route but I just don’t have a lot of confidence. If you have a moment my post is here if you have any thoughts on the parts list:
SSE Parts List Help
Will do!
Also, I'm using Tung-Sol EL34B's. I have them running at about 20w plate dissipation (80% of 25w) using 680 cathode resistors.
Also, I'm using Tung-Sol EL34B's. I have them running at about 20w plate dissipation (80% of 25w) using 680 cathode resistors.
I built a Tubelab SSE stock version. I set up the amp in ultra linear, with cathode feedback and Kt88 power tubes. I used the big Edcore output transformers. I found the amp to have solid deep bass, outstanding mid-range and an extended high end. No weakness in the sound. A real step up from the NAD amp I'd had before.
I had some troubles getting it working at first but George and others on the tubelab page here helped me get it going. I had built a guitar amp from a kit before but that's about all the experience I had. I'd recommend the SSE because of the sound quality of the amp and the help you receive from the community.
I had some troubles getting it working at first but George and others on the tubelab page here helped me get it going. I had built a guitar amp from a kit before but that's about all the experience I had. I'd recommend the SSE because of the sound quality of the amp and the help you receive from the community.
The general consensus is that the output transformer is the most important factor in defining the sound quality of any competently designed tube amp.
I've read many times, over and over, that the output transformer in the Dynaco Stereo 35 amp, the Z-565, is a real sleeper, the best Dyna made. The ST-35 amp uses EL84 output tubes in 'ultralinear' configuration, which just about everyone agrees 'sounds good' within their power limitations (about 10 watts of real continuous power per channel). That's enough for most speakers of middling sensitivity being played in a small to medium sized room (unless you need rock concert/dance club playback levels).
The Dyna ST-70 delivers twice as much power, which could be necessary if you have lower sensitivity speakers playing in a larger room. Of course the ST70 uses a larger, more expensive output tube (EL34), an expensive rectifier tube (GZ34), runs at higher voltages, consumes more power from your electricity provider, and so is more expensive on every front.
I don't think you can go wrong with a Dyna ST-35, especially now that the output transformers are made with 4 ohm secondary taps, which makes them compatible with today's commercially available loudspeakers. The ST-35 has enough power for almost all rational speakers played at reasonable volume levels, and it isn't complex. Sounds like a good first tube amp project to me.
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Tubelab makes circuit boards for a similar design to the ST-35, called the Simple Push-Pull (SPP). There's a lot of information on the Tubelab site about that design type.
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I've read many times, over and over, that the output transformer in the Dynaco Stereo 35 amp, the Z-565, is a real sleeper, the best Dyna made. The ST-35 amp uses EL84 output tubes in 'ultralinear' configuration, which just about everyone agrees 'sounds good' within their power limitations (about 10 watts of real continuous power per channel). That's enough for most speakers of middling sensitivity being played in a small to medium sized room (unless you need rock concert/dance club playback levels).
The Dyna ST-70 delivers twice as much power, which could be necessary if you have lower sensitivity speakers playing in a larger room. Of course the ST70 uses a larger, more expensive output tube (EL34), an expensive rectifier tube (GZ34), runs at higher voltages, consumes more power from your electricity provider, and so is more expensive on every front.
I don't think you can go wrong with a Dyna ST-35, especially now that the output transformers are made with 4 ohm secondary taps, which makes them compatible with today's commercially available loudspeakers. The ST-35 has enough power for almost all rational speakers played at reasonable volume levels, and it isn't complex. Sounds like a good first tube amp project to me.
--
Tubelab makes circuit boards for a similar design to the ST-35, called the Simple Push-Pull (SPP). There's a lot of information on the Tubelab site about that design type.
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Ive built both a bob latino st-120 and a tubelab se. They are very different amps and as far as the build goes, the tubelab has slightly less documentation but the build itself is considerably easier than the point to point wiring of the dynaco build. I dont think a build could get much easier than the SSE.
They are both great sounding amps but in different ways and with different purposes.
They are both great sounding amps but in different ways and with different purposes.
@birkbott
I did the same mental exercise as to doing a build for the first time in a long time*.
Info:
I can solder. I know how to read a schematic. I've got good quality meters**
No other special stuff.
I'm half-way through a Tubelab SSE build right now. And it's a blast!
It's *extremely* well documented & supported on the forums.
*a Heathkit DX-60 kit.
** Fluke
I did the same mental exercise as to doing a build for the first time in a long time*.
Info:
I can solder. I know how to read a schematic. I've got good quality meters**
No other special stuff.
I'm half-way through a Tubelab SSE build right now. And it's a blast!
It's *extremely* well documented & supported on the forums.
*a Heathkit DX-60 kit.
** Fluke
birkbott, I didn't even mention that the SSE sounds fantastic.
I'm driving an old pair of Buschhorn MKII's (single driver, folded horns) that I built twenty years ago. I just put a new pair of Fostex FE108EZ's in (about 92db) last spring. More volume than I can currently use.
It's a true audiophile-grade amp at a ridiculous budget price. But, you can certainly spend over $1K on it if you want with boutique transformers, capacitors, and NOS tubes.
I'm driving an old pair of Buschhorn MKII's (single driver, folded horns) that I built twenty years ago. I just put a new pair of Fostex FE108EZ's in (about 92db) last spring. More volume than I can currently use.
It's a true audiophile-grade amp at a ridiculous budget price. But, you can certainly spend over $1K on it if you want with boutique transformers, capacitors, and NOS tubes.