This little amp was given to me some time ago by a friend to whom it was given previously and didn't want it...so I got it for nothing. As it was, it worked but something was clearly wrong with it as all the output valves got very hot quickly along with the power transformer, not to mention the judicious audio distortion! Being a technician from way back I realized that a little restoration would probably restore its original performance.

So slowly but surely components were measured and changed, if needed. My Dynaco was built as a kit around 1971 or thereabouts and components from that time had issues with value 'stability'. Most of the resistors had drifted very 'high' in value and they were replaced with metal film resistors of the right circuit values according to the circuit diagram that came with the amplifier. Replacing the resistors helped, but the problems remained. In the end, I also ended up replacing all the coupling capacitors with high voltage polyester capacitors of the right values.

Every one of the original coupling capacitors was very electrically 'leaky' and was badly messing up the various bias voltages, thence causing all the overheating and audio distortion! All other components were fine. I was amazed how cool the amplifier now ran and without any audio distortion!

It's a very nice little amp. As the output power is small, it helps to team the amp with efficient loudspeakers. Sound quality wise, it's a superb little amplifier. Yes it sounds like a valve amp, but isn't that what valve amps are supposed to sound like?! Yes. Lovely, smooth and laid back sound with no obvious noise and/ hum!

Warm mellow tube sound. Low price.

Would like more power.

This is my second tube amplifier. My first was a Mcintosh 30 wpc integrated amp. I sold that amp many years back to cover tuition at college. I had been running an AMC 2N100-5 power amp through an Accuras pre-amp and DCM time window speakers. The DCM's are now hooked up to the Dynaco and the high dollar stuff is going up for auction on Ebay. I like the Dynaco, enough said.

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Affordability

Power output

I found myself listening to a lot of my collection in a different light. No, this is not the last word in amplifiers but, this little baby does have a measure of magic to offer. The bass is soft and wooly. The highs are rolled off. The mids are nectar from the gods. My snobby audiophile friends who have more money than time to invest into such an adventure were blown away when the right type of music was played. If your musical collection needs to be heard with a nice little twist to it, try one of these beauties.
The admission price will only set you back 200-300 dollars. Now, please, if you know how to spend this amount of money on a different component and get this type of satisfaction, I'm in there!!!

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Heathkit

This is my first Tube gear and I will proably keep it for the rest of my life (I am 24). The sound is fuller and easier to listen to then anything I have heard.

If you find one and you like the way it sounds, buy it!

I'm tired, so I'll keep this short. This is a decent little amp that sounds really good on some moderately sensitive speakers that I've tried. It's a lot rarer than the ST-70, looks "cute", and, according to many people in the know, may be the best sounding amplifier that Dynaco produced. The transformers (I forget the model number for these) are supposed to be really good sounding, wide bandwidth units. I've tried these on dynamic speakers and a pair of Klipsch Heresies (see my review in the speaker section).
They sounded great on Dana Model 1's, Mission 731i's, and a pair of modified Optimus LX-4 Pros (discontinued), but nowhere as good as the Audio Note Kit One did on these speakers. Of course, the Kit One is much more expensive. At the time I bought my ST-35, about six years ago, I paid about $160.00 for it. Prices are undoubtedly higher, now, if you can find one. Curiously, the ST-35 fell flat with the 96db efficient Klipsch Heresies. I listened to this setup for some time when my Audio Note Kit One went down and thought that it sounded pretty good. The sound was thicker and fuller than that of the Kit One and the bass seemed a little more solid. After a while, though, the sound was just too smooth and thick for the Heresies, which made music played through the setup sound flat and somewhat lifeless. This was reinforced when I got my Kit One up and running. With the Audio Note in the system, I could finally enjoy the music, again, instead of being bothered by the congested sound of the ST-35 through these speakers. This may not be the best amp to use with revealing horns.

The ST-35 worked quite well with the other inexpensive dynamic speakers I tried it on. Though not as captivating as the Kit One through the Heresies, the ST-35 did play music very well with the other speakers. The sound was solid and warm with good drive and a nice tube-tone.

If you do have or get one of these amps, you might want to try the following: change out the cheapy bluish-green coupling caps to some better caps. If I was doing this today, I would look into the inexpensive Chinese paper-in-oil caps that Steve sells at Angela Instruments (www.angela.com) as my first choice. Otherwise, try some film caps that are not too expensive. When I did this six years ago, there wasn't the proliferation of good caps like there is today. I had a choice between MIT and Wondercap. I got some Wondercaps. I didn't want to spend too much modding this amp because it's a very good amp, but not a great amp. I feel even more strongly today. You can do what you want, but I wouldn't go putting Audio Note/Jensen oil caps or Hovland Musicaps in this amp. It's just not worth it.

Also, you can change the resistors to Roederstein or Beyschlag or Dale metal film. Some people say don't change out the old carbon resistors in the ST-70 or ST-35 or the amp will sound mechanical. It's a matter of taste, I suppose. I thought it sounded more open and dynamic when I changed to good audiophile grade metal film. Even so, I still think the sound is too smooth. Don't use Holco for this, as they tend to fail more frequently when used with more than 100v through them, so I hear. Again, I wouldn't use anything too expensive, like Caddock, Vishay, or exotic carbon or tantalum films...not worth it, in my book. Also, change out the two old rectifier diodes to some ultra-fast soft recovery units.

Before you do any of this, however, BE SURE YOU KNOW WHAT YOU'RE DOING. You've heard this before, but the voltages in there could kill you. Even if they don't, a poor or botched job could burn down your house. Be careful. I modded my amp by looking at the values of the components and replacing them value for value. I recommend that you get a download of the schematic from the website of Chris and Sue Beck. Unfortunatly, I've left all my link information in another city, so I don't have the URL. Be sure to thank them if you find any information on their website useful.

Over all, I think the Dynaco ST-35 is a very good little amp that plays music very well, especially when modified. I especially recommend it for friends and relatives who are careful enough to unplug it after they're done listening to it (it has no on/off switch), and who want a nice, warm, relaxing tube sound. This amp, when coupled with the right speaker, can sound solid, warm, and enjoyable...perfect for the listener who just want to listen to music and not worry about gear. For those with better equipment, the ST-35 will probably not make it into your setup. You might put it in there every now and then just for kicks, but it may be too smooth and not dynamic enough after you've had something better in your system. Overall, I would give the ST-35 three and a quarter stars...so much for my short review. It's time for me to go to bed.

Sound

obscurity, man it's old.

I found this little gem on my way home from work maybe 2-3 years ago - it was on a trash heap. I scooped it up, took it home and it's been powering my system ever since. The bass is fine and the smooth highs are what I really like about this amp. Since I've started using this amp my search for the optimum sound (and consequent spending) ended. Funny how that is.

Sadly it's out of balance so I've been poking around the web looking for answers. I'm not an electronics whiz so it's kind of hard going.

I gave it 5 stars for value because heck, I found it on a trash heap and it's sweet. No greater bargain than that.

I gave it 5 stars overall because it truly is far better than I imagined, the sound is pretty incredible especially considering the low wattage it puts out.

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