technics SU-V85A class A amp, opinions
- Thread starter jgarcia
- Start date
I have a Technics integrated SU-V91 (IIRC), and it has the "New Class A" circuitry. This is Technic's non-switching output, similar to what others were doing at the same time. I don't think Pioneer had a special name for their non-switching amps. JVC called it something Class A.
I have mine running the JBL L00's, isn't that a coincidence.
I have mine running the JBL L00's, isn't that a coincidence.
dr.ido
Well-Known Member
I've got a couple of Technics New Class A amps. I seem to remember the ads of the time also made a big deal of the unusual "heat pipe" heat sink, but they didn't use it in all of them.
Sony has at least a couple of similar designs. One that I have even uses the same output modules. They called them Legato Linear or Super Legato Linear.
Sony has at least a couple of similar designs. One that I have even uses the same output modules. They called them Legato Linear or Super Legato Linear.
Charles7318
New Member
Technics SU-V85A
Last month I picked this set up at the pawn store for $89. I discovered that this is the model with the transformer and filter capacitor upgrade. What I find rather strange is that the rail voltage is close to + and - 70V. The high voltage itself is not really weird but the fact that there are only two output transistors per channel that are rated at 160v CE 120w dissapation and 12a collector current each. Quite wimpy for this application indeed. Usually the engineer uses at least two sets of paralleled outputs in this type of application. Also the filter caps are rated at 71v. Not much voltage headroom there. What I have done is replace the caps with 80v with just a bit more capacitance. The second thing that I will do is to replace the outputs with higher ratings to try to make up for the lack of two paralleled outputs. The ones are from On Semiconductor that are the same TO-247 package but have a dissapation of 230w CE voltage of 200v and collector current of 15A. The gain is a little higher so this should work. Also a small pesky issue is that there is a light but knoticeable ripple (power amp hum) that fades out completely in about three minutes. My engineer friend looked over the schematics and said that it has some design issues in the power supply. Even so, it does have a wonderful sound that I like very much. This model was only available to the military PX.
Last month I picked this set up at the pawn store for $89. I discovered that this is the model with the transformer and filter capacitor upgrade. What I find rather strange is that the rail voltage is close to + and - 70V. The high voltage itself is not really weird but the fact that there are only two output transistors per channel that are rated at 160v CE 120w dissapation and 12a collector current each. Quite wimpy for this application indeed. Usually the engineer uses at least two sets of paralleled outputs in this type of application. Also the filter caps are rated at 71v. Not much voltage headroom there. What I have done is replace the caps with 80v with just a bit more capacitance. The second thing that I will do is to replace the outputs with higher ratings to try to make up for the lack of two paralleled outputs. The ones are from On Semiconductor that are the same TO-247 package but have a dissapation of 230w CE voltage of 200v and collector current of 15A. The gain is a little higher so this should work. Also a small pesky issue is that there is a light but knoticeable ripple (power amp hum) that fades out completely in about three minutes. My engineer friend looked over the schematics and said that it has some design issues in the power supply. Even so, it does have a wonderful sound that I like very much. This model was only available to the military PX.
