Hello to you all
I had a mosfet amp for a about 15 years with TL071 opamp stage, BD138-139 drivers and hitachi j50-k135 powerfets. (Audio en Techniek SC-10 amp)
2 years ago decided to change this amp to a hybrid: SRPP 6922 tubes with choke power supply and paper in oil coupling caps to the fets. I Build from standard parts and scrap-parts lying around
(powersupply- caps: 2 in series of 25V with 10K bypass resistor and so on): Sound was wonderfull and detailed, due to the fets and tubes very clear in performing the harmonics of instuments.
Last week upgraded all scrap parts by new parts from Schuro.de
Cathode decoupling: Standard Philips lytic changed for Elna Cerafine, in powersupply Panasonic HA 10000uF 50V, bypassed them with 0.1 uF MKP, standard cheap decoupling caps of 470uF 63V changed to Panasonic 470uF 50V HA.
Maybe you guess already: sound was shut in, more transitor-like, sharp treble, no more detailed bass........After a burn-in time of a few days no improvement.....
Another remarkable point: The hybrid- amp doesn't like NON-OS anymore!! It sounds bad now, before mods beatifully detailed and natural!!
Tubee(JW)
Now I am very confused to this, and my view on (quality?) audio components is totally changed, standard components can sound wonderful.
To come back on my question: What should be a decent burn - in time for paper in oil coupling caps, and the lytic PS caps?
I had a mosfet amp for a about 15 years with TL071 opamp stage, BD138-139 drivers and hitachi j50-k135 powerfets. (Audio en Techniek SC-10 amp)
2 years ago decided to change this amp to a hybrid: SRPP 6922 tubes with choke power supply and paper in oil coupling caps to the fets. I Build from standard parts and scrap-parts lying around
(powersupply- caps: 2 in series of 25V with 10K bypass resistor and so on): Sound was wonderfull and detailed, due to the fets and tubes very clear in performing the harmonics of instuments.
Last week upgraded all scrap parts by new parts from Schuro.de
Cathode decoupling: Standard Philips lytic changed for Elna Cerafine, in powersupply Panasonic HA 10000uF 50V, bypassed them with 0.1 uF MKP, standard cheap decoupling caps of 470uF 63V changed to Panasonic 470uF 50V HA.
Maybe you guess already: sound was shut in, more transitor-like, sharp treble, no more detailed bass........After a burn-in time of a few days no improvement.....
Another remarkable point: The hybrid- amp doesn't like NON-OS anymore!! It sounds bad now, before mods beatifully detailed and natural!!
Tubee(JW)
Now I am very confused to this, and my view on (quality?) audio components is totally changed, standard components can sound wonderful.
To come back on my question: What should be a decent burn - in time for paper in oil coupling caps, and the lytic PS caps?