Bruh. I read that thread. My head is spinning!! :-O But yeah, that is exactly what I need to do is learn what all that means. Don knows MUCH about this topic. I get lost easily in that discussion.
That's great info! Thanks. I have much homework to do. Old hard head doesn't soak it up that easy any more.The Tek scope is plenty adequate for repairs. A popular 4 channel digital scope is a Rigol ds1054z at only $350. It's a 50mhz scope that can be cracked to 100mhz. The thing I don't like about it i the trace is not as fine as the analog scopes such as the Tektronix. Ed Blackwood commented on this earlier in a post on scopes here.
If you have a scope then you need a signal generator. I have a an HP 204 which covers 1 HZ to more than 100KHZ at reasonably low distortion. It's an oscillator not a function generator. An alternative that I've used in a pinch is an app on a phone and they're free. Another low cost option for a scope is a USB type. USB scopes
I bought a cheap portable 2 channel. Does most everything I ask it to.
https://www.ebay.com/itm/New-OWON-p...tbgeLx:sc:USPSPriorityFlatRateBox!85615!US!-1
It’s compact, I like that. And brand new! I’ve yet to take the plunge. Been hesitant. Concern for age related issues in my price range.
I don’t know anything about them either but got the impression somewhere that inexpensive new Chi-scopes were not worth owning. But if this one comes endorsed by Perry, it could be the one I should have.
I could endorse a 50 year old Tektronix 475 I used in the Navy but they are too old for me. could last 6 minutes, could last 6 months..... (where did I hear that before)? I have limited room and being portable, you can charge it up and move around with it..... Doesn't weigh a ton and it's new. For looking at the amps and stuff, or tracing a 2Khz signal through the preamp, it works tits.... Could I fix the space shuttle with it?? Probably not but then again..... I couldn't fix the space shuttle with any scope....
I bought a cheap portable 2 channel. Does most everything I ask it to.
https://www.ebay.com/itm/New-OWON-p...tbgeLx:sc:USPSPriorityFlatRateBox!85615!US!-1
Do you keep it plugged in to a power supply when you have it on the bench, or just run it off the battery pack?
That's great info! Thanks. I have much homework to do. Old hard head doesn't soak it up that easy any more.
The Tektronix I posted a pic of looks to go for under $150 shipped. Should I wait and get something different?
Yessir, just got this back to the bench. I work on a lot of speakers, had to take a break from this amp for a minute.Kevin, trying to get this thread back on your original topic. (the horror!!!)
While a scope is a useful tool to have in your toolkit, it is not essential to you fixing your current left channel problem as your recent right channel experience has proven. Still many things to be run down.
I'll start:
Have you checked each connection into the Phoenix connector to ensure you are grabbing wire and not the insulation on the wire?
Have you bypassed the relay on the DCP on the left channel?
Have you ensured that the +/-15V is getting to the left channel by looking at the output side of R40L and R41L?
Have you ensured that none of the resistors R35L, R37L, R36L, R39L and also that D13L is OK? Remember what that misplaced ground did to the other channel.