AP35 surprise
Posted: Mon Jan 14, 2019 3:59 am
A friend bought an AP35 with a broken channel and asked me to fix it. The problem was simply the output transistors, the emitter resistors and another pair of small resistors burned, After changing all this I took advantage of to change also the electrolytic capacitors, which were already many years old, the main ones of 4,700uF are exchanged for Elna LAO of 10,000uF and the 6 of 47uF in the pcb's by Jackon LHK Low ESR, also of 47uF.
The main capacitors and pcb's are glued with strong glue, as I did not have I used this double-sided adhesive tape, which also promises a strong bond:
http://mundoceys.com/producto/36/bricocinta
And this is where the surprise comes: the sound became much warmer and more pleasant, it really makes you want to make long listens. I have changed capacitors for better ones many times and I have never found this effect, so I attribute it to the tape. The tape is 1mm thick and is made of what looks like some kind of silicone, I suppose its effect has been to dampen some kind of vibrations and that is the origin of the sound improvement.
I put it here in case someone wants to repeat it, it's easy, cheap and harmless, you can easily go back if the result does not please us.
My friend is really delighted with his AP35, what is described as 'a delight'.
Regards
The main capacitors and pcb's are glued with strong glue, as I did not have I used this double-sided adhesive tape, which also promises a strong bond:
http://mundoceys.com/producto/36/bricocinta
And this is where the surprise comes: the sound became much warmer and more pleasant, it really makes you want to make long listens. I have changed capacitors for better ones many times and I have never found this effect, so I attribute it to the tape. The tape is 1mm thick and is made of what looks like some kind of silicone, I suppose its effect has been to dampen some kind of vibrations and that is the origin of the sound improvement.
I put it here in case someone wants to repeat it, it's easy, cheap and harmless, you can easily go back if the result does not please us.
My friend is really delighted with his AP35, what is described as 'a delight'.
Regards