Wildwood SB 50 Mods

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i_b_tulloch

New member
I have the WW SB50W, 3 channel amp. I love it as it is, but compared to a stock boosted plexi it still sounds pretty polished to me. I was wondering if there were any mods that could make it more raw, and less refined like a vintage boosted plexi? Preferably any mods would be switchable between stock and modded.

Thanks
 
Yeah. Response (i.e. NFB ) Switch would help. Easiest way do do this is to put a mini toggle switch by the impedance selector. The switch selects the NFB source, stock comes off the output jack, and modded comes off the 4 ohm tap.

Another spot to fix is the 500pf paralleled to the 100k on V2 socket. You could easily add a toggle switch there to toggle that cap in/out.
 
Thanks guys. The response/NFB mod makes sense.

What would toggling in/out the 500pF paralleled with the 100k at V2 socket do to the sound?
 
i_b_tulloch":kwe4qafd said:
Thanks guys. The response/NFB mod makes sense.

What would toggling in/out the 500pF paralleled with the 100k at V2 socket do to the sound?
Click to expand...


Dave uses these 500pf caps in various spots to "Polish" the sound, so toggling it out would make it more raw. There's another one on v2B cathode. To recap V2A has one across the plate resistor (on the socket) as I already mentioned, and V2B has one on the cathode. The one on V2B is connected to a switch on the BE100, its the voice switch, or part of it I should say.
 
A NFB mod / response switch or pot is probably going to get you where you want to go.

If you want to mess with the other caps as above, I have a few observations:
With the cap on the plate resistor, I would lift one leg and test it, vs putting it on a switch. There's a lot of DC there, and those little toggles are gonna be dicey with that amount of DC voltage. And it'll pop like a bitch.
For the cap on the cathode follower, yes Dave has it on a switch, but the switch is controlling a relay that sits right beside the cathode resistor ( along with the cap), so the lead length for the cap connection is minimal.
I've messed with this cap on a switch by running leads out to a front panel switch ( no relay ), and with the cap dis-connected, it oscillates like a MOFO.
Again, probably better to just lift a leg and see how it sounds, and then make the decision either in or out.
YMMV.
 
fusedbrain":qsjo758b said:
I've messed with this cap on a switch by running leads out to a front panel switch ( no relay ), and with the cap dis-connected, it oscillates like a MOFO.
Again, probably better to just lift a leg and see how it sounds, and then make the decision either in or out.
YMMV.
Click to expand...


Yeah, I've done it without the relay many times with no problems. I used shielded wiring. Thats the way Dave done it before he went to the hybrid PCB.

There is also ways to do the caps on the plate loads without pops.
 
CNutz":6i9oh4qh said:
fusedbrain":6i9oh4qh said:
I've messed with this cap on a switch by running leads out to a front panel switch ( no relay ), and with the cap dis-connected, it oscillates like a MOFO.
Again, probably better to just lift a leg and see how it sounds, and then make the decision either in or out.
YMMV.
Click to expand...


Yeah, I've done it without the relay many times with no problems. I used shielded wiring. Thats the way Dave done it before he went to the hybrid PCB.

There is also ways to do the caps on the plate loads without pops.
Click to expand...
Yeah, OK cool. I was just relating my experiences. I figured the cap and wiring on the cathode follower was acting like an antenna. I just left the cap in. In a high gain circuit it's a great little tone shaper.
I'm still not comfortable putting those kinda DC voltages on those little switches.
YMMV
 
fusedbrain":34f676ls said:
I'm still not comfortable putting those kinda DC voltages on those little switches.
YMMV
Click to expand...

That + - voltage mini-toggle on the PhilX amp has pretty much full plate DC on it :shocked: I've seen the inside of both the mini, and large toggles, and really I think you run the risk of shock from a faulty switch being about equally.

But if you really wanted to have no DC on the switch for switching that 500pf plate cap, you could replace the 500pf with 2 1000pf in series with the switching done between them.
------/\/\100k/\/\------
--|1n|--Switch---|1n|--
 
CNutz":3uwb1s6q said:
fusedbrain":3uwb1s6q said:
I'm still not comfortable putting those kinda DC voltages on those little switches.
YMMV
Click to expand...

That + - voltage mini-toggle on the PhilX amp has pretty much full plate DC on it :shocked: I've seen the inside of both the mini, and large toggles, and really I think you run the risk of shock from a faulty switch being about equally.

But if you really wanted to have no DC on the switch for switching that 500pf plate cap, you could replace the 500pf with 2 1000pf in series with the switching done between them.
------/\/\100k/\/\------
--|1n|--Switch---|1n|--
Click to expand...
Yikes!!! Ok, obviously Dave knows what he's doing .
I'm just going by the voltage rating on the switches I have, and it ain't very much lol! ( good quality switches from Mountain and e switch )
On the cathode cap switch, yes you can position the cap to block the dc in front of the switch. For the plate cap, that's an elegant safety solution you posted. :thumbsup:
Never considered that.
Would it not still make an insane popping noise though?
 
fusedbrain":3okuciuk said:
CNutz":3okuciuk said:
fusedbrain":3okuciuk said:
I'm still not comfortable putting those kinda DC voltages on those little switches.
YMMV
Click to expand...

That + - voltage mini-toggle on the PhilX amp has pretty much full plate DC on it :shocked: I've seen the inside of both the mini, and large toggles, and really I think you run the risk of shock from a faulty switch being about equally.

But if you really wanted to have no DC on the switch for switching that 500pf plate cap, you could replace the 500pf with 2 1000pf in series with the switching done between them.
------/\/\100k/\/\------
--|1n|--Switch---|1n|--
Click to expand...
Yikes!!! Ok, obviously Dave knows what he's doing .
I'm just going by the voltage rating on the switches I have, and it ain't very much lol! ( good quality switches from Mountain and e switch )
On the cathode cap switch, yes you can position the cap to block the dc in front of the switch. For the plate cap, that's an elegant safety solution you posted. :thumbsup:
Never considered that.
Would it not still make an insane popping noise though?
Click to expand...


The voltage/amp ratings on the switch has a lot to do with determining life expectancy. For example rated to 10,000 cycles @ 125v 6 amps of current, something like that. Even most of the big toggles only show 125-250v printed on them. Also the high voltages in our amps, have low current so these switches still operate in reasonable range. If you think arcing is an issue consider 500vdc can only gap across 0.05mm through air.
 
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