Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Gareth81 on July 30, 2023, 08:08:35 am

Title: Why no cold clipper in the hotswitch mod?
Post by: Gareth81 on July 30, 2023, 08:08:35 am: I’ve just been comparing the jcm800 circuit with Doug’s hotswitch mod. The hot switch seems like a better design as it preserves the V1a topology for the low gain option, but why doesn’t it have the 10k cold clipper cathode resistor?
Title: Re: Why no cold clipper in the hotswitch mod?
Post by: sluckey on July 30, 2023, 10:35:10 am: Only the shadow knows. Why not ask the shadow?
Title: Re: Why no cold clipper in the hotswitch mod?
Post by: Gareth81 on August 01, 2023, 03:18:40 am: Okay, well maybe I should have phrased the question: What difference would the cold clipper 10k resistor make in this situation?
Title: Re: Why no cold clipper in the hotswitch mod?
Post by: pdf64 on August 01, 2023, 08:10:10 am: It would make the low input kinda weak, same as a 2204, no longer like plugging into a 4 hole Marshall.
Title: Re: Why no cold clipper in the hotswitch mod?
Post by: Gareth81 on August 01, 2023, 05:20:35 pm: Quote from: pdf64 on August 01, 2023, 08:10:10 am
It would make the low input kinda weak, same as a 2204, no longer like plugging into a 4 hole Marshall.

The low input wouldn't go through the cold clipper. Doug's hotswitch repurposes the second half of V1 as a second gain stage, so the cold clipper would go there. When this isn't switched in, it has the stock preamp topology. After reading about the cold clipper, I was just wondering why this wasn't included.
Title: Re: Why no cold clipper in the hotswitch mod?
Post by: sluckey on August 01, 2023, 05:41:59 pm: I told you only the shadow knows. I guess you didn't ask the shadow. All we can do is speculate. OK. I'll try. Cause he doesn't like 'em? Probably wanted the nastiest buzzsaw amp he could get. Why cripple the amp? Just speculating. Any one else? :icon_biggrin: