Ibanez Starfield Valve Pre Amp

[edy_wheazel]

A while ago I got a rack unit with this toy, well, to be precise it's actualy the chassis containing the transformer and an empty pcb.





I was curious about the schematic, but that was a dead end. At some point, in the forgotten depht of the internet, I came across the schematic of the Ibanez Starfield SVA1, it's a 2x50W valve amp and preamp, and the preamp has the same controlls as mine. I compared the first part of the preamp schematic with my empty pcb, looks like the preamp is the same. I redraw the schematic of the preamp (it was spread on several pages) and this is what I think the Ibanez Starfield Valve Pre Amp looks like (see attachment).
The voltages are from the SVA1, the Starfield Valve Pre Amp has a transformer which has the following voltages: 1x260V, 2x17.5V, 1x6.3V
The 2x17.5V section goes to a +/-15V stabilizer, I'm guessing it powers an OpAmp filter (have to check this on my empty pcb) and the clean and OD looper, not shown on my schematic.
Well, have fun with it!

[Dirk_Hendrik]

Thanks! That must have been quite some work!

[edy_wheazel]

Continuing.

As you can see on the front panel, there is a "FILTER" switch.



The schematic of the filter:



The next stage after the filter is the looper.



I'm guessing it had a separate PCB, on the main one (preamp + filter) there is nothing for that. I'm gonna trace the looper from the SVA-1.

Have fun with this!

[davdevalle]

Hi edy. I have a starfield sv1a and it has stopped working. I know nothing about Amps but I want it fixed and so all info will help. and you posted a schematic for this -and some extra filter pictures and schematic in your next post. But they are not sHowing up anymore... do you still have these? My emai, is dav@davdevalle.com

A while ago I got a rack unit with this toy, well, to be precise it's actualy the chassis containing the transformer and an empty pcb.

[ Image ]

[ Image ]

I was curious about the schematic, but that was a dead end. At some point, in the forgotten depht of the internet, I came across the schematic of the Ibanez Starfield SVA1, it's a 2x50W valve amp and preamp, and the preamp has the same controlls as mine. I compared the first part of the preamp schematic with my empty pcb, looks like the preamp is the same. I redraw the schematic of the preamp (it was spread on several pages) and this is what I think the Ibanez Starfield Valve Pre Amp looks like (see attachment).
The voltages are from the SVA1, the Starfield Valve Pre Amp has a transformer which has the following voltages: 1x260V, 2x17.5V, 1x6.3V
The 2x17.5V section goes to a +/-15V stabilizer, I'm guessing it powers an OpAmp filter (have to check this on my empty pcb) and the clean and OD looper, not shown on my schematic.
Well, have fun with it!

[edy_wheazel]

Repost pics: