Great post rankaudio, I should hire you as my marketing director!
A few years ago I started playing around with the Dynaco Stereo 120 out of simple curiosity. I have owned and listened to more than 100 amplifiers ranging from vintage Pioneer and Pilot tube amps to solid state Bob Carver and Sansui. Each having its own unique sound and signature. I like the sound of tubes best.
After doing about 4 of these I dialed in on what worked best in the Stereo 120. I was astounded. I don't recall hearing any solid state amplifier before that sounded like this one. These simply don't sound like a solid state and certainly after the "modernization" is applied. They far surpass the original 120 amps sound and performance, it will eat a Dynaco 70 for lunch. Had I not heard this with my own ears I could not have believed it.
My simple theory is that a circuit can only be as good as it's components allow, a weakest link scenario. A good circuit with bad components will not see its potential. I have applied this theory to my Stereo 70 amps and found vast improvements, why not apply this to the 120? Haffler had a knack for getting the most out of the least, he was a genius of circuit design and he hit it on the head again with the 120. The 120 has it's problematic reputation due mainly to budget oriented signal path components and a temperamental and unreliable power supply that is difficult to work on at best. Introducing a wonderful modern regulated power supply, new circuit boards with premium components and adding huge increases in overall capacitance allows this amp to breath deeply, like a Khumbu valley Sherpa.
Not to be satisfied with a great sound alone, I take great time and effort to make these amps look quite unique. How many solid state amps would you want to leave the top off of, like a tube amp, to marvel at its appearance? Whether you like it or not this amp is a "giant killer" in its class. Quite frankly this amp should fetch at least a thousand dollars considering the cost to build let alone the time and effort it takes.
I completely disassemble these, hand polish the chrome, removing every bit of blemish possible. You cannot ever get it all because of the type of plating used over the mild steel. Some of the cosmetic flaws are underneath the chrome and show through, they're permanent. I try and always start with a great condition chassis, some are obviously better than others though. I chemically and manually clean every screw, nut and washer, every clamp, the heatsinks, everything gets attention and detail. The transformer is tested and detailed accordingly, the cover is refinished and treated to a custom aluminum badge identifying the amp as "enhanced". New feet, new power cord, new blue LED pilot bulb. I even deox the fuse holder, I get down in there deep, all the way around. I reuse the original outputs. New better input jacks are installed, these are custom made just for the 120.
I also offer a volume control that allows this amp to be used stand alone, no preamp, with a line level source like a tape deck, cd player, mp3 and so on. Even a turntable with an integrated preamp works great since that gives a line level output signal. It's a very versatile amp with the volume control feature. It's also very compact and easy to find a suitable place for where other larger amps could not be used.
I recently had a batch of custom color circuit board made to build some "limited edition" versions, as if they weren't already this way. I have a few sets of black, white, and yellow in addition to the standard red, green and blue ones. I even had black and red power supply boards made and also have these in the standard green. With complimentary colored wiring these new colors should look really special. I am currently in the process of putting one amp together using the new white PCBs and using a black power supply board but new build orders have stacked up, since I own this unit myself it has been shelved temporarily until I get caught up. I do have one Stereo 120 ready and it is available right now on my site, check it out at:
https://funtasticvintronics.com/collections/amplifiers/products/dynaco-stereo-120-enhanced
A few years ago I started playing around with the Dynaco Stereo 120 out of simple curiosity. I have owned and listened to more than 100 amplifiers ranging from vintage Pioneer and Pilot tube amps to solid state Bob Carver and Sansui. Each having its own unique sound and signature. I like the sound of tubes best.
After doing about 4 of these I dialed in on what worked best in the Stereo 120. I was astounded. I don't recall hearing any solid state amplifier before that sounded like this one. These simply don't sound like a solid state and certainly after the "modernization" is applied. They far surpass the original 120 amps sound and performance, it will eat a Dynaco 70 for lunch. Had I not heard this with my own ears I could not have believed it.
My simple theory is that a circuit can only be as good as it's components allow, a weakest link scenario. A good circuit with bad components will not see its potential. I have applied this theory to my Stereo 70 amps and found vast improvements, why not apply this to the 120? Haffler had a knack for getting the most out of the least, he was a genius of circuit design and he hit it on the head again with the 120. The 120 has it's problematic reputation due mainly to budget oriented signal path components and a temperamental and unreliable power supply that is difficult to work on at best. Introducing a wonderful modern regulated power supply, new circuit boards with premium components and adding huge increases in overall capacitance allows this amp to breath deeply, like a Khumbu valley Sherpa.
Not to be satisfied with a great sound alone, I take great time and effort to make these amps look quite unique. How many solid state amps would you want to leave the top off of, like a tube amp, to marvel at its appearance? Whether you like it or not this amp is a "giant killer" in its class. Quite frankly this amp should fetch at least a thousand dollars considering the cost to build let alone the time and effort it takes.
I completely disassemble these, hand polish the chrome, removing every bit of blemish possible. You cannot ever get it all because of the type of plating used over the mild steel. Some of the cosmetic flaws are underneath the chrome and show through, they're permanent. I try and always start with a great condition chassis, some are obviously better than others though. I chemically and manually clean every screw, nut and washer, every clamp, the heatsinks, everything gets attention and detail. The transformer is tested and detailed accordingly, the cover is refinished and treated to a custom aluminum badge identifying the amp as "enhanced". New feet, new power cord, new blue LED pilot bulb. I even deox the fuse holder, I get down in there deep, all the way around. I reuse the original outputs. New better input jacks are installed, these are custom made just for the 120.
I also offer a volume control that allows this amp to be used stand alone, no preamp, with a line level source like a tape deck, cd player, mp3 and so on. Even a turntable with an integrated preamp works great since that gives a line level output signal. It's a very versatile amp with the volume control feature. It's also very compact and easy to find a suitable place for where other larger amps could not be used.
I recently had a batch of custom color circuit board made to build some "limited edition" versions, as if they weren't already this way. I have a few sets of black, white, and yellow in addition to the standard red, green and blue ones. I even had black and red power supply boards made and also have these in the standard green. With complimentary colored wiring these new colors should look really special. I am currently in the process of putting one amp together using the new white PCBs and using a black power supply board but new build orders have stacked up, since I own this unit myself it has been shelved temporarily until I get caught up. I do have one Stereo 120 ready and it is available right now on my site, check it out at:
https://funtasticvintronics.com/collections/amplifiers/products/dynaco-stereo-120-enhanced