pics of the actual unit in question

 
I'm finally back in San Diego where I've been keeping this VTX amp, so I can get a look at it and start to map out the transformation process in earnest.  There have been a few surprises already...


At least I have the footswitch; couldn't remember if I had it or not.  Regardless, I'll be putting in panel switches so that the footswitch is not required.

I had wisely already added some wheels to this amp.  My my, but it's heavy!  WTF, Peavey?




As you can see, someone before me has changed both of the speakers.  Guess they didn't care for the tone -- I sympathize, but I doubt this helped much.  The one which is not blown is a Celestion G12L-35.  I presume that means it's rated for 35W.  It's too bad, because the original Peavey Scorpions or Black Widows or whatever, which the amp came with, would have been rated (I think) for over 100W each.  So even with one blown, I could have changed this amp into a 1x12, with no issues from the 4x6L6 power output.  But now, well of course I'm going to make it into a 1x12 anyway, using the Celestion, and I'll just have to be careful not to blow it.  I virtually never need anything like 100W anyway; the most likely scenario to blow it would be if someone borrows the amp, like in jam situations where not everyone brings their own amps (conveniently), and people like me end up providing the "backline", de facto.  (I also always bring a soldering iron to gigs, so if you have any loose jacks or busted cables, I'll fix those for free because I can't say no to a fellow musician in a bind.)  Oh well, if it does blow, I bet I can get a used replacement Peavey Scorpion for cheaper than another Celestion!


Comments

Post a Comment

Popular posts from this blog

final interconnection, first power test

Image
Connecting the new circuitry to the VTX chassis.  Most connections are through the 12-position "Euro" terminal strip, except heater power (to the left) which is hard-wired. First power-up, with no tubes inserted.  LEDs ahoy!  This just verifies that the +15V power supply is working, and I haven't made any grievious errors in the wiring. I verified that the channel-select 3-way switch works, turning on and off the yellow and green LEDs on the VTX, and the preamp-select 3-way works, turning on and off the white LEDs (yes, those are white, not blue as they appear in the camera). And I verified that the HV supply works, by taking it out of standby and observing that the blue LED of the RGB pilot light illuminates.  (It's a bit dim with the 10M resistor though, I guess I need to decrease the resistance; gotta take care with the power dissipation...)
Read more

schematics of my mods

Image
  Again, caveats from the previous post apply here as well.  Most significantly, I have not yet built the boost circuit, nor even verified whether the VTX power transformer can handle the additional heater current load.  And some of the wiring of the phase inverter, vis a vis nfb, has not yet been implemented or tested.  So these circuits are to some extent, aspirational.
Read more