I stand corrected on the 72V.
No wonder they blew up so easy, only 60V rated outputs.
FYI, when you drive an amplifier to full output,the output that is 'on' has low voltage across it, and the output that is 'off' has to stand off the rail-to-rail supply voltage.
Hate to tell someone this but a HK Citation 12 was solid state
The $429 price on the McIntosh listed at Russels's site was from when it was discontinued in 1979, not what it sold for in 1967
The Crown was $10 more than the assembled Dynaco
The first SWTPC Tiger came out in 1967, quasicomp, later it went comp output stage. Those were only $115 for a pair of monoblocs, or $175 factory assembled.
I built more than a few of these on the desk in my dorm room, and paired them with a kit built Dyna PAT4 (untill SWTPC came out with their preamp).
No wonder they blew up so easy, only 60V rated outputs.
FYI, when you drive an amplifier to full output,the output that is 'on' has low voltage across it, and the output that is 'off' has to stand off the rail-to-rail supply voltage.
Hate to tell someone this but a HK Citation 12 was solid state
The $429 price on the McIntosh listed at Russels's site was from when it was discontinued in 1979, not what it sold for in 1967
The Crown was $10 more than the assembled Dynaco
The first SWTPC Tiger came out in 1967, quasicomp, later it went comp output stage. Those were only $115 for a pair of monoblocs, or $175 factory assembled.
I built more than a few of these on the desk in my dorm room, and paired them with a kit built Dyna PAT4 (untill SWTPC came out with their preamp).
Folks, the Dyna 120 was a DOG! I don't say that often, BUT it came out very early, before complementary symmetry and any circuit sophistication at all. I was told by a Dyna engineer to stick to tubes, at the 1965-66 Hi fi Show in San Francisco, but he may have referred to the PAT4, which was introduced about the same time. I can't be sure after almost 40 years.
At that time I owned two Dyna mk-3 tube power amps and I used a Dyna Pas3 tube preamp, until I replaced it with a Levinson JC-2. I certainly stood behind the Dyna tube stuff, but solid state started off badly, for two essential reasons: First, the transistors were too expensive at the time. Two, the resident engineers did not know how to design with transistors very well yet. Probably one of the first really successful solid state designs in that era was made by Harmon Kardon. Yes folks there really are very poorly perfoming designs sometimes put into the audio marketplace. This has little or nothing to do with taste or preference.
At that time I owned two Dyna mk-3 tube power amps and I used a Dyna Pas3 tube preamp, until I replaced it with a Levinson JC-2. I certainly stood behind the Dyna tube stuff, but solid state started off badly, for two essential reasons: First, the transistors were too expensive at the time. Two, the resident engineers did not know how to design with transistors very well yet. Probably one of the first really successful solid state designs in that era was made by Harmon Kardon. Yes folks there really are very poorly perfoming designs sometimes put into the audio marketplace. This has little or nothing to do with taste or preference.
I'll give it credit for one thing...the Dyna 120 was the first high-fidelity amplifier I ever heard (connected to some VOTT Altec's). Since all I had heard previously was cheap all-in-one consoles, the 120, along with the Altec's and a nice Dual T-Table, I was floored and thus began my hi-fi addiction.john curl said:
Many years later, after exposure to some real amplifiers, I had a chance to listen again to a ST120. Pretty disappointing, but the ST120 still holds a place in audio history, both personal and global.
dynaco 120
I recently re-read thest reports on the dynaco stereo 120. there was a 80 watt version. similar but with a smaller unregulated power supply.
it was based on RCA steel voltage regulator transistors developed for military and industrial applications. Dynaco claimed that it did not have the "transictor sound" ( a fault) or many of the other problems of then- current transistor amps. Nor was it possible to tell the difference between it and tube amps. One weakness, if you could call it that ,was the power supply almost equalled the voltage rating of the transistors. Information has been published on the "unofficial dynaco site" listing the replacement parts to upgrade the amp for greater dependability.
Dynaco later sold a st-150? that conmtained the upgraded parts.
Because i am retired and no longer work inb the industry, i cannot easilg get a set of these parts. the transistors have to be tested to a specific range of beta and should be matched to a certain degree,
I think it would be a mistaks to re-do the amp as a chip/module based amp.
I recently re-read thest reports on the dynaco stereo 120. there was a 80 watt version. similar but with a smaller unregulated power supply.
it was based on RCA steel voltage regulator transistors developed for military and industrial applications. Dynaco claimed that it did not have the "transictor sound" ( a fault) or many of the other problems of then- current transistor amps. Nor was it possible to tell the difference between it and tube amps. One weakness, if you could call it that ,was the power supply almost equalled the voltage rating of the transistors. Information has been published on the "unofficial dynaco site" listing the replacement parts to upgrade the amp for greater dependability.
Dynaco later sold a st-150? that conmtained the upgraded parts.
Because i am retired and no longer work inb the industry, i cannot easilg get a set of these parts. the transistors have to be tested to a specific range of beta and should be matched to a certain degree,
I think it would be a mistaks to re-do the amp as a chip/module based amp.
Now this IS interesting
Bouht mt ST 120 ''71 as a Kit..Along with a Pat $ .. Both Gave Years (30) of trouble free ..as in NO repairs ever.
Now the Pat 4 was simply not the best.. Problems with Cartridge matching surfaced early... but it was acceptable.
I used this to power a Pair of Tannoy GRF's.. A reasonably easy load.. possibly accounted for the reliability?
Having heard all the Dissing..I'm somewhat taken by surprise.. The sound of that setup was Surprisingly Good.. All who heard it were amazed... certainly not the V best but No Dawg either.. a surprising number of "boutique Units' produced lesser sounds..
Although I'm thinking that it was the Tannoys that Were the basis of the sound quality.. these seem to work with most anything.
In fact it wasn't 'till the early 80's that I had to accept that there Was better sound readily available. In '90 I had the 120 circuit 'revitalised by yhe people at Sonic Frontiers.. (for Free Basically a Parts swap, a few Value changes and a whole lot of Bypassing... the result was Serious improvement. (have Parts list/instructions if someone is Serious . Also have The Am Audio articles on Upgrading the old Bipolars with something more Moderne.. But it looked to be way too much trouble..( most AA Mods involve a Wheelbarrow full of Parts, by my observations, and this one was no exception ;-) Besides The SF mods really improved the sounds.
Using a Stepped attenuator instead of the Pat 4 was also a 'good' move. I have little love for the Pat4 tho.
Performance? Bass is decent in a tube like way.. deep but a wee bit boomy, not a lot of the Current needed to adequately control those big Cones, Mids are Acceptable, not ideal but decently believable and Highs are extended and quite sweet..
Again Dunno why all the dissing/animosity... My copy at least, has done yeoman service.. and even when i fired it up the other day (it's just about 35 Now).... it still sounded as good as most any Mid Fi .
Mebe a Dawg.. but a darned lovable one
Bouht mt ST 120 ''71 as a Kit..Along with a Pat $ .. Both Gave Years (30) of trouble free ..as in NO repairs ever.
Now the Pat 4 was simply not the best.. Problems with Cartridge matching surfaced early... but it was acceptable.
I used this to power a Pair of Tannoy GRF's.. A reasonably easy load.. possibly accounted for the reliability?
Having heard all the Dissing..I'm somewhat taken by surprise.. The sound of that setup was Surprisingly Good.. All who heard it were amazed... certainly not the V best but No Dawg either.. a surprising number of "boutique Units' produced lesser sounds..
Although I'm thinking that it was the Tannoys that Were the basis of the sound quality.. these seem to work with most anything.
In fact it wasn't 'till the early 80's that I had to accept that there Was better sound readily available. In '90 I had the 120 circuit 'revitalised by yhe people at Sonic Frontiers.. (for Free
Basically a Parts swap, a few Value changes and a whole lot of Bypassing... the result was Serious improvement. (have Parts list/instructions if someone is Serious . Also have The Am Audio articles on Upgrading the old Bipolars with something more Moderne.. But it looked to be way too much trouble..( most AA Mods involve a Wheelbarrow full of Parts, by my observations, and this one was no exception ;-) Besides The SF mods really improved the sounds. Using a Stepped attenuator instead of the Pat 4 was also a 'good' move. I have little love for the Pat4 tho.
Performance? Bass is decent in a tube like way.. deep but a wee bit boomy, not a lot of the Current needed to adequately control those big Cones, Mids are Acceptable, not ideal but decently believable and Highs are extended and quite sweet..
Again Dunno why all the dissing/animosity... My copy at least, has done yeoman service.. and even when i fired it up the other day (it's just about 35 Now).... it still sounded as good as most any Mid Fi .
Mebe a Dawg.. but a darned lovable one
I don't post very often, but I thought I'd throw in a note. The first 120's used a 3055H which were industrial/military parts with a 90 volt collector voltage. The 3772 works well because the sustaining collector volatge is 80 volts. (one of those hidden values on the spec sheet.) I have several of these, six or seven, a couple I've had since the 70's. They may not sound the best to many folks, but as far as they're being usless, I doubt. I have modified these in several ways with good results, that's why I have so many. The tip mod, power supply mod, two different mosfet versions as well as both an original 3055H version and original 3772 version for comparison. I also have a couple of ST-80's, one stock and one mosfetted. The stock one doesn't sound much different from the two stock versions of the 120. My 3055H version has the same transistors it came with. One thing I have noticed is that if you curve match the 3772's they also last a long time, and if you curve match the drivers, side to side, they sound better. I have a Marantx 240, Phase Linear 200 and a Crown D-75 as well as a bunch of solidstate receivers of various vintage, using a CD player as a music source and depending on which speaker system is used the sonic differences can become pretty slight, I can't say the same using LPs as the source. At least to my ears.
If you don't like the 120's, okay, but for experimentation everything has possibilities. I've had as much fun modifying and listening to these as all the different tube amps I've played with.
mike
If you don't like the 120's, okay, but for experimentation everything has possibilities. I've had as much fun modifying and listening to these as all the different tube amps I've played with.
mike
st 120
I think there is too much and sometimes biased opinion and too litte fact.
a lot of really junky stuff was made over the years and soold by department stores and " hi-fi" dealers. most of this stuff sounded terrible.
It was brand name stuff made and sold for a price. when it died and it would die, it was often unreparible by design.
compare high-end audio to exotic cars. which do yoy want a ferrarri or a ford or chevy. which one works. few of us have really " golden ears"
and most of those who do DON'T! and if we did we might noit have the training/experience to tell the difference. Much source material is flawed.
reminds me of the " hi fi" expert who went to his first live concert.
when asked how he enjoyed it, he said the loudness control was set wrong!
if you read this I would appreciate recieving mod info on older audio equipment. contact me. I am also interested in the swtpc amps.
I think there is too much and sometimes biased opinion and too litte fact.
a lot of really junky stuff was made over the years and soold by department stores and " hi-fi" dealers. most of this stuff sounded terrible.
It was brand name stuff made and sold for a price. when it died and it would die, it was often unreparible by design.
compare high-end audio to exotic cars. which do yoy want a ferrarri or a ford or chevy. which one works. few of us have really " golden ears"
and most of those who do DON'T! and if we did we might noit have the training/experience to tell the difference. Much source material is flawed.
reminds me of the " hi fi" expert who went to his first live concert.
when asked how he enjoyed it, he said the loudness control was set wrong!
if you read this I would appreciate recieving mod info on older audio equipment. contact me. I am also interested in the swtpc amps.
A very interesting and variable point of view i could read
I thank you all, because this theoricall and practical conversation is very interesting to me.
We all know that there are amplifiers that turn us very tired to long time hearing.
I have in my imaginations that brain go correcting a lot of errors, and this can make you "feel" tired.
How long you can hear something, and how loud it can be without disturb you, can be some indication (one between many indications) of how much some equipment can be bad.
I do not believe in Golden ears, really i believe, in better brain signal processing that some guys can have related others.
Example:
Science already told us that female hear high frequencies better than us.
Also they told we have better hearing around 2K...exactly the mains frequency of our small babies crying...some animal need to protect our family.
Also was verified that over 60 years old...people older than that, cannot hear frequencies higher than 14 Kilohertz...but you can see that there are a lot of people hearing, not only depends from the level, because this "do not hear" is dependable of the volume, but also depends of the brains capacity to amplify, detect and perceive small signal, as inside ears, there are some mechanical problems that reduce transducer (hearing transducer cells) level related higher frequencies....those guys we call golden ears, many of them are old and experienced, and detect details that many of us cannot do.
Some brain exercise, connected to motivation, capacity of focusing, to concentrate mind in something.
But all those things produce fatigue....and this is, in my mind, some way to evaluate quality.
thank you all, a very good thread this one turns...old and full of informs and plenty of good people cooperating...i feel very good with that, this makes this forum very special.
regards...and thanks
Carlos
I thank you all, because this theoricall and practical conversation is very interesting to me.
We all know that there are amplifiers that turn us very tired to long time hearing.
I have in my imaginations that brain go correcting a lot of errors, and this can make you "feel" tired.
How long you can hear something, and how loud it can be without disturb you, can be some indication (one between many indications) of how much some equipment can be bad.
I do not believe in Golden ears, really i believe, in better brain signal processing that some guys can have related others.
Example:
Science already told us that female hear high frequencies better than us.
Also they told we have better hearing around 2K...exactly the mains frequency of our small babies crying...some animal need to protect our family.
Also was verified that over 60 years old...people older than that, cannot hear frequencies higher than 14 Kilohertz...but you can see that there are a lot of people hearing, not only depends from the level, because this "do not hear" is dependable of the volume, but also depends of the brains capacity to amplify, detect and perceive small signal, as inside ears, there are some mechanical problems that reduce transducer (hearing transducer cells) level related higher frequencies....those guys we call golden ears, many of them are old and experienced, and detect details that many of us cannot do.
Some brain exercise, connected to motivation, capacity of focusing, to concentrate mind in something.
But all those things produce fatigue....and this is, in my mind, some way to evaluate quality.
thank you all, a very good thread this one turns...old and full of informs and plenty of good people cooperating...i feel very good with that, this makes this forum very special.
regards...and thanks
Carlos
dynaco 120 and listening quality
as i said before, much source material is flawed and may even be distorted deliberately for an "effect".
classicical music is a rare exception where the true and real sond of the intstruments, some designed and built ceturies ago, is expected to be accurately reproduced.
I remember mention of distortion devices such as reverb and "fuzz" in guitar amps.
I also remember hearing that the famous " transistor sound" was really crossiover distortion. -- when the ac signal goes from + to -.
Not in a speaker cossover circuit.
I have noted that there are folks who talk about tube audio being the "pure-est" and little attention or credit is given to solid state - transistor or IC based amplifiers. for example, there are at least 4 aftermsrket KITS for the dynaco st-70 tube amps and none-- that I am aware of-- for the dynaco solid-state amps.
true the st-120 was a very early transistor amp design.
dynaco used RCA steel transistors ( copper and aluminum-based transistors have better thermal heat sinking properties, but the greater expansion/contraction of these metals tends to cause earlier failure). Steel transistors last longer, if you like the dynaco st-120 this is a good thing. if you Don't like it you wish the amp had a "quicker total failure mode" .
another problem of the st-120m noit having to do with sound quality was the limitations of transistors at that time. there is a list of parts available to upgrade the amp to "st-150" ??? - type parts.
I am old enough to have lost hearing above 14k and possibly lower.
My ears were never golden. I tolerate noise as i used to listen to distant am-mw and sw am stations as a hobby. I don't LIKE it but i tolerate it. I want whatever music I listen to to clear and undistorted. years of the crappy quality of 90% of devices has let me be a but tolerant and let my mind ignore problems.
at this time in my life, i am pleased that a component works and cannot expect perfection as I cannot pay for that level of nice.
as i said before, much source material is flawed and may even be distorted deliberately for an "effect".
classicical music is a rare exception where the true and real sond of the intstruments, some designed and built ceturies ago, is expected to be accurately reproduced.
I remember mention of distortion devices such as reverb and "fuzz" in guitar amps.
I also remember hearing that the famous " transistor sound" was really crossiover distortion. -- when the ac signal goes from + to -.
Not in a speaker cossover circuit.
I have noted that there are folks who talk about tube audio being the "pure-est" and little attention or credit is given to solid state - transistor or IC based amplifiers. for example, there are at least 4 aftermsrket KITS for the dynaco st-70 tube amps and none-- that I am aware of-- for the dynaco solid-state amps.
true the st-120 was a very early transistor amp design.
dynaco used RCA steel transistors ( copper and aluminum-based transistors have better thermal heat sinking properties, but the greater expansion/contraction of these metals tends to cause earlier failure). Steel transistors last longer, if you like the dynaco st-120 this is a good thing. if you Don't like it you wish the amp had a "quicker total failure mode" .
another problem of the st-120m noit having to do with sound quality was the limitations of transistors at that time. there is a list of parts available to upgrade the amp to "st-150" ??? - type parts.
I am old enough to have lost hearing above 14k and possibly lower.
My ears were never golden. I tolerate noise as i used to listen to distant am-mw and sw am stations as a hobby. I don't LIKE it but i tolerate it. I want whatever music I listen to to clear and undistorted. years of the crappy quality of 90% of devices has let me be a but tolerant and let my mind ignore problems.
at this time in my life, i am pleased that a component works and cannot expect perfection as I cannot pay for that level of nice.
What you refer to as 'Hard to listen to' Is in my experiences are highs that are shrill and irritating.. no arguement there.
There are LOTS of "currently in production" Hi priced
"audiphool approved" units that do exactly that.. sadly.
Seems there are many who equate Bright and shrill with quality sounds
Hey! what ever gets Sales apparently.
This could be a reaction tho to Male hearing losses. tho.. IF you went to an Audiologist you might be surprised to find that Few if Any can still hear close to 20Hz by their 21st Birthday.. and 15 HZ is the norm for 40 yr old Males.. and by 60 ?... well.. Mate
Women apparently Don't have similar hearing losses.
Explains in large part whyy Few females bother much with Audio Sillyness.. they are far more interested in the Music.. if at all.
Serious suggestion: ALWAYS take a woman with you when Auditioning Audio stuff.. For a non hearing impared viewpoint.. but the real trick then would be to actually ..Listen.. to the opinions thus generated
There are LOTS of "currently in production" Hi priced
"audiphool approved" units that do exactly that.. sadly.
Seems there are many who equate Bright and shrill with quality sounds
Hey! what ever gets Sales apparently.
This could be a reaction tho to Male hearing losses. tho.. IF you went to an Audiologist you might be surprised to find that Few if Any can still hear close to 20Hz by their 21st Birthday.. and 15 HZ is the norm for 40 yr old Males.. and by 60 ?... well.. Mate
Women apparently Don't have similar hearing losses.
Explains in large part whyy Few females bother much with Audio Sillyness.. they are far more interested in the Music.. if at all.
Serious suggestion: ALWAYS take a woman with you when Auditioning Audio stuff.. For a non hearing impared viewpoint.. but the real trick then would be to actually ..Listen.. to the opinions thus generated
If you get a chance patch an RTA or anyother kind of spectrum analyzer in between your preamp amp. You will find there is so little content above 14k you are missing very little. In fact the main thing you will be missing are the harmonic distortion artifacts (from speakers, amps etc) derived from the lower parts of the signals spectrum.
That's why us old guys can still enjoy the music.
sonic quality
I was pleased that I see or is it HEAR agreement, even from destoyer x ( carlos) who tends to say just what he thinks.
since i am a really Old guy and cannot hear as a one did. even 22k with a audio generator. even 15,575 ( tv sweep) cannot be hard or tv
sets don't have loose sweep cores any more.
I suppose the older and less FI amps and preamps are good enough for me.
when in 1955, i worked for a tv guy, he cared none at all for stereo as he had a severe hearing loss in one ear. I guess in a similar way some of the "acceptible" equipment is excellent as it exceeds my hearing.
my acceptance of a woman as beautiful is different because i cannot see perfectly either. many 7 out of 10 are now rated as really beautiful. at least i think so.
carlos, i know you are overrun with really beautiful women down there.
I was pleased that I see or is it HEAR agreement, even from destoyer x ( carlos) who tends to say just what he thinks.
since i am a really Old guy and cannot hear as a one did. even 22k with a audio generator. even 15,575 ( tv sweep) cannot be hard or tv
sets don't have loose sweep cores any more.
I suppose the older and less FI amps and preamps are good enough for me.
when in 1955, i worked for a tv guy, he cared none at all for stereo as he had a severe hearing loss in one ear. I guess in a similar way some of the "acceptible" equipment is excellent as it exceeds my hearing.
my acceptance of a woman as beautiful is different because i cannot see perfectly either. many 7 out of 10 are now rated as really beautiful. at least i think so.
carlos, i know you are overrun with really beautiful women down there.
Wdegrot, you are rigth, beautifull woman surrounds me...i am very lucky.
But near 55, slowly turning old..... you can understand what i mean...but beauty is fresh air in our lifes....love and beauty.
I was always lucky, this way i am always smilling in an idiotic way...but i have my reasons...some reserve of rememberings and pretty family.
Lucky...very lucky!
yes, i am
Carlos
But near 55, slowly turning old..... you can understand what i mean...but beauty is fresh air in our lifes....love and beauty.
I was always lucky, this way i am always smilling in an idiotic way...but i have my reasons...some reserve of rememberings and pretty family.
Lucky...very lucky!
yes, i am
Carlos
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