p11a
Dear as_audio
Do you still have the file for the p11a service manual? I'm looking to fix the transformer on one of my units and I'm thinking this schematic will help.
Dear as_audio
Do you still have the file for the p11a service manual? I'm looking to fix the transformer on one of my units and I'm thinking this schematic will help.
All went well on the p11a- the transformer developed a fault and was replaced by two series linked transformers to step down to the correct voltages - see photo for the voltage steps - Thanks for the schematic
Attachments
What was the problem - open primary? Then I'd guess the thermal fuse went. I can't imagine something sourced from Hypex (even if it was 15 years ago) would have been too inexpensive, that may have been worth finding someone who works on transformers for. Anyway, as long as you managed to cram everything back in there...
BTW, two "series linked" transformers? I assume you mean two in parallel, one for 27-0-27 and one for 16-0-16 secondaries?
P11a coupling capacitor specification
Many thanks to as_audio for the P11a schematic. One of my speakers was faulty, both drivers were working but very little bass from the main driver. All 4 coupling capacitors (22uF 50v) were faulty - very high ESR in excess of 100 ohms and once removed from the circuit the capacitance ranged between 0.5 - 2uF on each. I have temporarily replaced these with 33uF 50v (all I had in stock) and everything sounds great again.
I have since tested the same 4 caps on the other speaker (this still works) and the ESR again is very high. I have not removed from circuit yet to test capacitance.
The question is, why have all of these failed and should I replace them with a different spec electrolytic?
All the other caps seem to be in good visual condition with low ESR (in circuit), apart from the two 10,000uF caps which were all bulging but still working.
Many thanks
Many thanks to as_audio for the P11a schematic. One of my speakers was faulty, both drivers were working but very little bass from the main driver. All 4 coupling capacitors (22uF 50v) were faulty - very high ESR in excess of 100 ohms and once removed from the circuit the capacitance ranged between 0.5 - 2uF on each. I have temporarily replaced these with 33uF 50v (all I had in stock) and everything sounds great again.
I have since tested the same 4 caps on the other speaker (this still works) and the ESR again is very high. I have not removed from circuit yet to test capacitance.
The question is, why have all of these failed and should I replace them with a different spec electrolytic?
All the other caps seem to be in good visual condition with low ESR (in circuit), apart from the two 10,000uF caps which were all bulging but still working.
Many thanks
I bought Adam p22a monitors untested and got burned. One amplifier made smoke when powered. Now, it is all good. Both monitors work and I am happy with the sound.
First big thanks to user as_audio for schematics.
Here is what I learned about the p22a.
There are at least two different models sold as p22a.
The analog model where the amplifier runs on two chip-amps (TDA 7293). Also many NE5532 op-amps.
The digital model based on ICE amps.
The analog model does not have any extra air holes for cooling on the back metal plate.
The digital has cooling holes on the back.
At least the analog model was fixable. It does not contain any surface mounted components. Some tracks on the circuit board were burned and had to be replaced with patches. It took 3 hours to for repairmen to fix my amp. At least parts were cheap. The chip-amps are only 5 eur each. It is funny that the fine monitor runs on this 5 euro amplification. I found references that for example Linn used these in many amps.
First big thanks to user as_audio for schematics.
Here is what I learned about the p22a.
There are at least two different models sold as p22a.
The analog model where the amplifier runs on two chip-amps (TDA 7293). Also many NE5532 op-amps.
The digital model based on ICE amps.
The analog model does not have any extra air holes for cooling on the back metal plate.
The digital has cooling holes on the back.
At least the analog model was fixable. It does not contain any surface mounted components. Some tracks on the circuit board were burned and had to be replaced with patches. It took 3 hours to for repairmen to fix my amp. At least parts were cheap. The chip-amps are only 5 eur each. It is funny that the fine monitor runs on this 5 euro amplification. I found references that for example Linn used these in many amps.
Many thanks to as_audio for the schematics. I had a pair of p22a’s that were low output and one tweeter was barely outputting. Mine were the version p22a. My tech pal replaced the input capacitors, and power supply capacitors. That brought them back to life. Now I’m getting an imbalance in high gain volume. I’m having to turn down one speakers high gain pot all the way to match the other speaker with its high gain turned all the way up. It sounds like a boost in the 2k range. Any thought what this could be? Out of tolerance resistors?