Truthfully, boss, when they're this old - Replace _all_ the caps. The ones that read good today will not read good tomorrow. Just reset the clock now :)
the T stands for Transfer Function Modified. later amps were the TFM series. Bob modified the feedback path to mimick the sound of another famous amplifier brand. but never said which.
Just love the good old USA product, people did not hide the schematic and welcome to pick out the design problem and improve, now they close the door and make tons of stupid mistakes.
For all I know the "a" and "t" versions had a redesigned power supply and minor changes to the amplifier boards from the earlier units. The "t" version stood for transfer function which was to make it sound like the super expensive amplifiers (ad nauseam to me). Sure, you could mod it if you had a reason for doing so.
Hi there I have a pretty stupid question and its kind of long sorry. In the audio mag from oct 1985, easy to find at worldradiohistory with search for audio-1985-10 pdf , they have a longggg add from carver starting about page 40. It shows a diagram from power supply and explains how it works its wayyyy to long to copy here. They show 2 diodes not zeners and state that it clamps voltage to 80 volts on output. The repair schematic shows 3 bridge rectifiers for 3 voltages. They show 2 inductors in series with the input of transformer with a capacitor at junction between then going back to the other leg of the main power. I do not see that on repair schematic either. Later in this super long add, that I mistook for an article, it claims 80 percent total efficiency. My question to all this is crap yes ?? oh yea only shows 1 output voltage from secondary of transformer.
The ad shows just a simplified theory of operation schematic, not the actual circuit. The amp does what it is designed to do, but IMHO, all the extra parts are a possible additional point of failure.
Not really, they have a shelf life specified by the manufacturer and the rubber seal is usually guaranteed to maintain the perfect balance between enclosing the electrolyte and allowing for venting under normal operations for a period of 10-15years. Small print relating to that can be found in manufacturers data. They slowly deteriorate, whether in circuit, or not and should be formed prior to use, if kept on the shelf for more than a couple of years. Again, forming procedure details are included in the data sheet. The larger the capacitance, the less it seems to be affected by the aging process, but leakage current and ESR tend to slowly creep up in any case. Used capacitors recovered from a circuit, that were polarized at a considerably lower voltage, than nominal will undergo a spontaneous forming process and be severely underperforming, if run later at one closer to nominal.
@@johnsonlam For sure, if it was not for the fact that thermal expansion under normal operating conditions must be allowed for, hence not perfect, but nearly perfect seal is called for, thus 10-15years guarantee on the nominal properties of the seal and slow, but persistent loss of performance.
Truthfully, boss, when they're this old - Replace _all_ the caps. The ones that read good today will not read good tomorrow. Just reset the clock now :)
the T stands for Transfer Function Modified. later amps were the TFM series. Bob modified the feedback path to mimick the sound of another famous amplifier brand. but never said which.
Thanks!
Just love the good old USA product, people did not hide the schematic and welcome to pick out the design problem and improve, now they close the door and make tons of stupid mistakes.
Yep, big pain in the backside with all the mechanical stuff, chin up !....cheers.
almost forgot great video thanks again
They did not make that one easy to work on or fix. I'd be tempted to just snip the leads.
So what improvements did the T have ? Can it be modded ? Worth modding ?
For all I know the "a" and "t" versions had a redesigned power supply and minor changes to the amplifier boards from the earlier units. The "t" version stood for transfer function which was to make it sound like the super expensive amplifiers (ad nauseam to me).
Sure, you could mod it if you had a reason for doing so.
You have no vices. That is good.
Did you check R 45 the 4.7 ohm?
Yep. It's good.
Hi there I have a pretty stupid question and its kind of long sorry.
In the audio mag from oct 1985, easy to find at worldradiohistory
with search for audio-1985-10 pdf , they have a longggg add from
carver starting about page 40. It shows a diagram from power supply
and explains how it works its wayyyy to long to copy here. They show
2 diodes not zeners and state that it clamps voltage to 80 volts on
output. The repair schematic shows 3 bridge rectifiers for 3 voltages.
They show 2 inductors in series with the input of transformer with a
capacitor at junction between then going back to the other leg of the
main power. I do not see that on repair schematic either. Later in this
super long add, that I mistook for an article, it claims 80 percent total
efficiency.
My question to all this is crap yes ??
oh yea only shows 1 output voltage from secondary of transformer.
The ad shows just a simplified theory of operation schematic, not the actual circuit. The amp does what it is designed to do, but IMHO, all the extra parts are a possible additional point of failure.
is it a good idea to stock electrolytics ?
Why not if you got the cash? They will not wear out until they are in circuit. People still selling old SPRAGUE capacitors as NOS.
Not really, they have a shelf life specified by the manufacturer and the rubber seal is usually guaranteed to maintain the perfect balance between enclosing the electrolyte and allowing for venting under normal operations for a period of 10-15years. Small print relating to that can be found in manufacturers data. They slowly deteriorate, whether in circuit, or not and should be formed prior to use, if kept on the shelf for more than a couple of years. Again, forming procedure details are included in the data sheet. The larger the capacitance, the less it seems to be affected by the aging process, but leakage current and ESR tend to slowly creep up in any case. Used capacitors recovered from a circuit, that were polarized at a considerably lower voltage, than nominal will undergo a spontaneous forming process and be severely underperforming, if run later at one closer to nominal.
@@johnsonlam for that shelf life issue. they get dried up.
@@iceberg789 If the manufacturer did a good job to seal up the capacitor properly, it could last for 30 or 40 years without dried up.
@@johnsonlam For sure, if it was not for the fact that thermal expansion under normal operating conditions must be allowed for, hence not perfect, but nearly perfect seal is called for, thus 10-15years guarantee on the nominal properties of the seal and slow, but persistent loss of performance.
Not that it matters at all (so stop reading) but I think the name is pronounced "do bill yay". I think I might just adopt "do bill ee do", though.
Uhm. Nope. It's "Doobie-Leer", apparently. I know, nobody cares.