Put Q1 and Q2 in tester from first channel. They measure as resistors, apparently they are cooked. Make a new transistor sandwich
with new transistors. I have two types, one is all black plastic including the back. The other type are like what came with the kit, with a metal back, so I used them.
On to the "T" parts and LED for further testing. New LEDs to be delivered today I hope.
with new transistors. I have two types, one is all black plastic including the back. The other type are like what came with the kit, with a metal back, so I used them.
On to the "T" parts and LED for further testing. New LEDs to be delivered today I hope.
Somehow I neglected to order R19 replacements. 51 ohms. nutz Maybe I can use two 100 ohm pieces, side by side if it will fit location on board. One type of 100 ohm types I have are really tiny black ones, much smaller than originals. CMF 50100R00FHEK. 1/4 watt, but smaller than the 1/8 watt pieces.
Russellc
Russellc
Pretty tight location, these one types are very small. If it looks as though it will not be neat, I will order some and wait, after going through giant bag of resistors. Doesnt stand out like one I've seen go by, but wasnt looking for that either...if it goes with you, you can put two 100R in parallel
just do it neatly
T6 tests good. hfe=89, Uf 691 mV . I have replacements, may as well install new one. Does this mean R19 is OK? It isnt discolored, but looks can be deceiving.
I have T6 out, SOMETHING is going to have to be re installed, so I figure why not a new one....but IF no need (and only if) it would avoid removal process of resistor R19 that would be good, only if...
Russellc
I have T6 out, SOMETHING is going to have to be re installed, so I figure why not a new one....but IF no need (and only if) it would avoid removal process of resistor R19 that would be good, only if...
Russellc
Russel had powered on XA 252 and line preamp in front of it, with Volume pot dialed up
when P3 was powered, whatever turn-on transient it had, it was amplified with line preamp and sent to XA252 input
I'm thinking how to implement current limiting in push-pull emiter follower buffer stage in XA252, but still didn't found definitive solution
when P3 was powered, whatever turn-on transient it had, it was amplified with line preamp and sent to XA252 input
I'm thinking how to implement current limiting in push-pull emiter follower buffer stage in XA252, but still didn't found definitive solution
One way to prevent it is to follow normal startup/turn off sequence. It was total dumb thing I did. Didnt check that selector on mute...sadly it was set to phono. Getting ready to see if it is fixed. Looking at start up steps from post #1, do I need to ground both positive and negative like original start up?
0r is this just a first start thing? Seems logical this IS a new first start.
Russellc
0r is this just a first start thing? Seems logical this IS a new first start.
Russellc
it did take out one fuse in the IEC plug. The two 2.5 amp in each side were good. Actually, the one that blew still measures with continuity, but there is a "disruption" on the slo blow element, and a small smoke stain inside. That's plenty cooked for me.
Russellc
It really was avoidable. I think it is pretty normal, (at least with my turntable, that lifting album off platter can cause minor static
sparking noise. This happened with Pearl 2, Pearl 3 and Salas UFSP, as well as old tube preamps. So normally, I am all about muting it if not playing.
Just got in a hurry, Preamp not on mute, even worse, still selecting phono....it was not a small transient.
sparking noise. This happened with Pearl 2, Pearl 3 and Salas UFSP, as well as old tube preamps. So normally, I am all about muting it if not playing.
Just got in a hurry, Preamp not on mute, even worse, still selecting phono....it was not a small transient.