Layout 5th Generation 183

[Structo]

25

[andyhardy]

Thanks

[ampdork]

4 Ohm tap.

[CHIP]

Concerning the OD and PAB (manual / pedal) switches ,there's a different wiring scheme between the #183 and #124 layouts. Are both ways correct? Anyone know, why the difference?

[Structo]

On #124 the PAB switch is not wired correctly.

I don't think any here have ever figured out why HAD did it that way.
Apparently he did it like this on several amps.

It is missing the ground wire to make it work right.

On #183 it seems to be wired backwards if I am reading it right.

The up position should be manual on.

And of course if using toggle switches it would be wired like that since the connections are opposite of the position of the bat lever.

[CHIP]

Thanks Tom,
I'm using toggle switches, since I noticed the layout (#183) was labeled slide switches, I wired it opposite the layout.
So the way I did it is actually wrong, if using toggles?

So when those switches go to ground, that activates manual?

[talbany]

Chip/Everyone

The wiring of the layout in 183 is for the toggles and is correct..It was just mis labeled...
Corrected along with 4 ohm GNFB tap on OPT
and Lost the shielded cable on the master and changed a few wire colors..

Revision 9 now up..

Thanks...... Tony

[CHIP]

Thanks Tony,

O well, time to rewire the switches.

[talbany]

Thanks Tony,

O well, time to rewire the switches.

Yeah man Sorry!!.. It happens..

[KT66]

Tony et. al involved involved in making the 183 layout, thank you. I was working up a schem for it when I noticed the one in the files section by Jaysg - real pro looking, good job. I noticed a discrepancy between the layout and schem though that hasn't been mentioned, and that is the wiring of the PAB relay. The schem shows the normal way it is done, but the layout doesn't match it. Normally the 2 red wires are connected at the PAB board and the 2 yellows are too and when the relay is activated they are disconnected except for the 22m anti-popping resistors that remain between each set of matching colors. The layout however shows reds and yellows connecting at the relay and the 22ms are in a strange spot also. I would guess that HAD used a relay with a different contact layout than the ones we normally see in the layouts here and that is the reason for the discrepancy ?

It was previously mentioned in this thread that the rock/jazz switch is different too, but I'm sure most realized that it is electrically the same as normal after staring at it for a little while like I did.

[CHIP]

Tony,
When comparing the layout and the schematic, I think the schematic is showing the Standby switch before the 2- 330mf PS caps. The layout shows the switch after the caps. Does the scem. need edited?

Thanks

[talbany]

Tony,
When comparing the layout and the schematic, I think the schematic is showing the Standby switch before the 2- 330mf PS caps. The layout shows the switch after the caps. Does the scem. need edited?

Thanks

Chip.. The Stby on the Dumbles is always after the Plate caps so my guess would be the schemo needs a revision..
Thanks..


Ryan
Sorry I must have missed your post.. Looking at it first glance it looks like he changed the layout on the PAB board (So much for cut and paste) Although the wire colors still don't make much sense.. Thanks for noticeing.. I'll take a closer look tomorrow and revise if need be..

Take care.... Tony

[Max]

I don't think any here have ever figured out why HAD did it that way.
Apparently he did it like this on several amps.

Hi Tom,

IMO the reason is that a functional "manual" position of the PB switch on the back, which switches the PB "on" without a footswitch connected, is not needed since this function is already provided by the middle position of the rock/jazz switch of amps like #124 and without the need of an active "manual" relay function.

And with a footswitch connected you can switch the PB on and off with the relay by using the footswich if the PB switch on the back is in the "pedal" position.

So when playing ODS amps like #124 I always leave the PB switch on the back in the "pedal" position. And if I want to activate the "PB" without the footswitch I simply use the middle position of the rock/jazz switch. On some amps with such a kind of circuit the rock/jazz middle position is labeled "PB" on some not, function is always the same. This is a usual feature of most (if not all) transition generation and 4th generation "classic" ODS amps.

I've attached a pic of such a "PB" label at the middle position of the rock/jazz switch of ODS #121 (picture source: Rob Livesey's site).

All the best,

Max

[Structo]

Interesting.

I do have an On-Off-On switch on my Rock/ Jazz and the middle off position is PAB.