DR: OT @ 2 Ohms/ 10" spkr Q.

[Sea Chief]

Ive also wired the pot as if the schematic is looking at the top, knob side.. and the layout diagram therefore is looking at the back side.

Can someone just check this is correct?

Thanks, SC

[Chuck H]

The diagram was side by side with a schematic. It's harder to get wrong if you reference to the schematic. As far as the diagram, you are correct. You are looking at the face of the rheostat. The whole diagram is done as if you are looking through a clear panel. As to the switch, fugget about it. Just toss the little on/off placard and write on the thing with a Sharpie or add some Dymo labels. That way you know which position is actually "bypass" and, more importantly, which jack is "in" and "out".

[Sea Chief]

Hi ChuckH- "a clear panel" Im not understanding idea of, apologies.

Ok can you verify: Ive wired the rheostat viewed from behind/ as per soldering terminal lugs etc, as per the layout diagram/ assumed this view is from the pot's rear side. Which is converse to the schematic. Correct?

[Sea Chief]

The diagram was side by side with a schematic. It's harder to get wrong if you reference to the schematic. As far as the diagram, you are correct. You are looking at the face of the rheostat. The whole diagram is done as if you are looking through a clear panel. As to the switch, fugget about it. Just toss the little on/off placard and write on the thing with a Sharpie or add some Dymo labels. That way you know which position is actually "bypass" and, more importantly, which jack is "in" and "out".

So are all dpdt switches numbered as mine is? (1 & 4 across top, 2 & 5 across middle, 3 & 6 btm), and the lower switch position of all dpdt toggle switches is ON?

[Chuck H]

I can't say that ALL are, but that is typical. If you think about how the switch is logically constructed physically inside it will make sense. When the switch lever is up you want it at the "on" indication. It doesn't matter anyway because you're not using it as an on/off switch. I only suggested that switch because it's easy to source and certain to be up to the job. Throw away the on/off placard and don't worry about it.

[Sea Chief]

I can't say that ALL are, but that is typical. If you think about how the switch is logically constructed physically inside it will make sense. When the switch lever is up you want it at the "on" indication. It doesn't matter anyway because you're not using it as an on/off switch. I only suggested that switch because it's easy to source and certain to be up to the job. Throw away the on/off placard and don't worry about it.

Well I think thats another US > UK t'other way round thing then (like LH drive etc). Here ON is defo the norm in the down position, as the switch labels indicate (albeit written upside down for some obscure reason).

Ok Ive whacked it thru the Champ-as-Chimp in my lab.. and hey it works! nice one ChuckH. It sounds (with max attenuation) like its pretty dark above vol 8 (out of vol 12, even with a strat) but thats not bad as 8 is about max vol anyway here I can go, and I was expecting treble loss. Its defo got some brown sound now! splendid. And -the contraption- (piffle!) just warm too after 20 mins at max.

Now to tentatively put with my DR. my knees are a bit trembly about this tbh.

So is it ok to use with both a 4 Ohm and a 16 Ohm amp too then?

[Chuck H]

It's idealized for an 8 ohm load. Your amps should be fine with a 2:1 or 1:2 impedance mismatch. ie: 8 ohm ideal into a 4 ohm or 16 ohm load. Most DR's are set up for 8 ohms. Which is why I offered the circuit with component values for 8 ohms. If yours is hard wired for 16 ohms it should still be fine, but not ideal. If your DR has an impedance switch then set it for 8 ohms when using the attenuator.

The Champ will be fine too with a 4 ohm speaker requirement into an 8 ohm resistive load.

[Sea Chief]

Just tried with the DR (mine only made as an 8 Ohm amp). Mmm.. barely any difference attenuator on or off. I can -just- discern some very mild OD with DR vol at 6.5 (with max attenuation) but its getting loud so I have to back off the gtr vol a bit.. which means I'm back at square clean/ exactly as it sounds at vol 2.

I'm going to try with the 16Ohm 15w DOM once Ive got the plugs re-ended to go into the contraption.

[Sea Chief]

ChuckH- I wasnt meaning using a 4 Ohm spkr, &/ or a 16 Ohm spkr with the DR. I was meaning I have 3 amps, a Champ (4), DR (8), and DOM (16).

So Im still not clear on whether its safe to use for the 4 Ohm amp, & the 16 Ohm amp.

[Chuck H]

If the attenuator isn't making the amp quiet it is wired wrong and could damage any amp you plug into it.

[Chuck H]

I just re-checked my drawings for errors. I'm pretty sure they're correct. But I think there may have been a previous drawing with an error (oops). Double check against this one.

[Sea Chief]

No, it is making the amp quiet(er) but either I dont get much OD with this DR with this spkr (tho I have tried, with a different P12Q on a table if you remember/ as a brief test for the bad reverb hum, and there was plenty of OD under vol 4 even, albeit treby & shrill as it lay on the table.. but without shaking the room either).. or I cant reach it even with the attenuator.

The attenuator works, as I just used it with the Champ to decent effect. The plan tho is to use with the DR. Is it meant to attenuate right down to 0 as it were?

[Sea Chief]

I just re-checked my drawings for errors. I'm pretty sure they're correct. But I think there may have been a previous drawing with an error (oops). Double check against this one.

Thanks ChuckH. Yes thats the one I used, checked it all over 3x and it seems to work ok. Its just even dialing the DR vol up to 6.5 Im barely getting any OD I can hear, even digging into the strings. Its the usual scenario- Im so used to it I just expect it with every amp.

Ive so exhausted with these amps- Ive got the Champ to OD, at last (without needing to dial in vol 11 to get there too and take out the window).. so a result of sorts & I may keep it (but it does sound like a piddly kids/ toy amp to me). I think I might sell the lot tbh and just get a good MV amp. I cant afford a minimass thing.

[Chuck H]

The 1R (or .5R in another drawing) prevents getting to zero volume. It also tames the really glitch action of the rheostat at full rotation. But your DR shouldn't be louder than, say, a loud, but un mic'd singing voice. A quiet shout maybe.

I just want to note here that you have had trouble getting the Champ to OD well too. Maybe it's ODing now, some, but not as much as it should. Now that you can turn up the DR you note that it isn't ODing much either.?. You went round and round with your dark sounding SG too. Single coils won't OD either of those amps like a rock album. But an SG with humbuckers should obliterate the tone into a full square clip. Unless you always use that guitar with the volume knob rolled back (in which case any proper evaluation is out the window) you absolutely should be getting huge distortion from the DR with a humbucker equipped SG plugged into it. Unless one or both are not in proper working condition.

But we've been around this block already. I'm just wondering how many obvious signs it's going to take before you realize that the SG is probably in need of repair. Those may not even be dark pickups (unless they're straight up broken). The problem may be elsewhere. I don't care if you bought it new. I don't care if Jesus opened it up and said "It is good". The only way to know if it's right is to either have the knowledge and experience to know, take it to someone professional that does or compare it to an identical, known working model.

[Sea Chief]

Thats all rather patronising Chuck. I've enough knowledge & I've enough experience too. You imply its me, the guitar, everything but the amp. How many times does it need me to say that its not me, I can play pretty well (32 years) & I know perfectly well how to set up a gtr absolutely fine (just spent an hr hand-filing brass tele saddles down so it plays spot on for eg). There's nothing "wrong" with the SG nor anything to "repair". Again; Ive had gibson after gibson in my time I know how they should sound, '78 335, '68 Melody maker, '84 SG Std, all types.. and this silly-dark muddy SG which aint going to change for all the tea in china, & is simply NOT a true/ or correct SG tone due most probably to the overdense/ overtly heavy wood + bad choice of their cheapest p/us. Its morelike a mongrel Les Paul Jnr. Not me 'setting it up wrong' or anything either. 'Period' as you guys say. You assume I played the amps with the SG but I havent touched the SG for a week. The Champ above 8 sounded as dark as chocolate with the attenuator, the treble completely lost even via strat mid positions. It IS the amps. It is NOT any guitar.

The Champ -finally- using the attenuator, sounds like it should. The DR tho, as I said for some reason wont OD even right up at vol 6 with the attenuator. Not a hint. At 6.5 theres a hint/ it starts yes. But by this stage its too loud to be reachable.