Fender PA100 Metamorphosis..

[dschwartz]

Hi every one!!!
After 4 months of hard work i finished (almost) a complete tube amp, using an old fender pa100 amp parts.
I made this for a friend (well.. client) who bought that amp, and needed something special, a versatile, vintage-modern amp (he plays blues and shred). So i designed the hole amp with this features:

- Clean channel: bassically a twin reverb channel, but with a presence control and a mid shift switch.
- Drive Channel: 2 modes, Blues and Modern, the blues mode has 3 gain stages and modern has 4 (blues + boost triode), also, with mid shift and presence.
- Tube FX loop
- Tube Reverb
- Channel footswitch
- POwer amp: very much like the original pa100 power section, but changed the phase inverter and added a big sag resistor. It pulls 100W at 4 Ohms. No negative feedback (for a more vintagey sound)

Now, the story:
the original amp (well, this is one i found on the net, but it is identic)



After a lot of cleaning, dismembering, cutting, i stripped down the chassis:


I made the preamp with a strip board and molex connectors as terminals, like point 2 point..like this. It turned out pretty good and small.:



i tried to do the same pfor the PS, but it was too dangerous and unreliable.. si i made this PCB:


then started working on the amp:










i hope to post some soundclips soon!!!!!!

[theehman]

Nice job all around, but especially on the front panel graphics!  You should be proud!

[Mark Hammer]

Beautiful.  Simply beautiful.

Well done my friend.

[petemoore]

  That's what I'm typing about ! !
  Guten Strong...looks good !
  How hot does the 'bake' resistor [between the caps] get ?

[dschwartz]

  That's what I'm typing about ! !
  Guten Strong...looks good !
  How hot does the 'bake' resistor [between the caps] get ?

ehmm...i don´t know, i´ve never played it for more than a couple of minutes..and if i did, i´m not very confident of getting that near to the PS..i´ve got a couple of shocks and rather stay clear from that area..its a 20W 220 ohm resistor..frankly i don´t think its a very noticeable effect..but probably cause it´s 100W, and the effect should be noted at higher power levels..

every time i look inside the chassis i think.."how in hell i got this working..must be like more than a thousend connections in there"..well it works, and quite good!! this thing is almost noiseless (thanks to RG and aiken amps grounding techniques). Bottom end is loud and proud, but not very tight cause there´s no NF, and power amp distortion kicks in very quick, this thing has to be played loud!!

[dschwartz]

  That's what I'm typing about ! !
  Guten Strong...looks good !
  How hot does the 'bake' resistor [between the caps] get ?

ehmm...i don´t know, i´ve never played it for more than a couple of minutes..and if i did, i´m not very confident of getting that near to the PS..i´ve got a couple of shocks and rather stay clear from that area..its a 20W 220 ohm resistor..frankly i don´t think its a very noticeable effect..but probably cause it´s 100W, and the effect should be noted at higher power levels..

every time i look inside the chassis i think.."how in hell i got this working..must be like more than a thousend connections in there"..well it works, and quite good!! this thing is almost noiseless (thanks to RG and aiken amps grounding techniques). Bottom end is loud and proud, but not very tight cause there´s no NF, and power amp distortion kicks in very quick, this thing has to be played loud!!

well i touched the resistor after a while playing it at a decent volume. i have to say it barely warms up..

[frank_p]

I thinked last week that if someone made something like this, by hand, he would certainly be a complete nut...
This is incredibly impressive...
Can't believe it     

[Auke Haarsma]

Amazing!

[dschwartz]

here are some videos of the amp :

http://www.youtube.com/results?search_query=blues+master+tube&search_type=