Hi xbearxau, Can one assume the Spk Protect is only for the SS follower? Another Query, I take it you have an original UA unit and you are going to compare this with the UA when finished? The UA with its 30R load concept is very good, I use a similar setup. But this unit you are building is Reactive...

Rotary sw maybe?
https://www.jaycar.com.au/2-pole-sealed ... y/p/SR1212
Can be preset for 2 pole 2 position to 2 pole 6 position.
I have used these in several builds and work well.
Phil.

Hey Fred,, I'm still bench testing a circuit using my ideas mixed with a few others and so far it's working well. Preamp is slightly modified Clean/Crunch channel of the SLO, Into my Modified HiWatt tone stack then into a PP 6V6. I Don't need or want the Lead as it's too much for my styles so only 2...

I Just noted that the above schematic (as well as the original) has no ground reference? :scratch: As I understand it pin 3 needs a path to Common to work,, but I could be wrong [smilie=a_whyme.gif] I don't know about the Rockman circuit but my old Nobels unit which is similar to this one had a 68k ...

Am I correct here? Is this how the circuit looks on Clean 1 before it hits EQ-1? Looks good to me, nothing like a highlight colour to follow the signal path. Good on you :thumbsup Phil. So basically Clean 1 before it hits the cab sim is just a Compressor with an input Buffer right? Its basically re...

I need a bit of advice and guidance from the valve (tube) gurus. Specs from Partridge datasheet P4131 8k a-a 43% taps max 10W P4133 8-9k a-a, 20% taps max 8W Q2. As as far as I can remember none of the guitar amps I have worked on have used screen grid taps, should I just ignore these and use scree...

Carvindc125 wrote: ↑29 Nov 2020, 05:12 Am I correct here? Is this how the circuit looks on Clean 1 before it hits EQ-1?

Looks good to me, nothing like a highlight colour to follow the signal path.
Good on you
Phil.

I am looking at the full schematic and admittedly I am not used to looking at a schematic drawn in this way. The switches and routing to them is throwing me off and confusing me. Is there anyway someone could be an amazing over achiever and Draw the schematic in sections like the edge, dst, and EQ1...

Also is there a complete schematic on the distortion section including where +6 and -6 is hooked up? the Full Schematic is on the very first post. :wink: Re the SST1 mockman it's close to the same,, as noted here by *Jarrod* he thought he needed more hi freq but ultimately found it was not needed. ...

Thanks Johan, Wired up like you said for dual voltage supply, the preamp works to some effect as it should, aside from one fault. The Volume control now seems to only find its maximum gain in the centre position, dial up or down from there and it just cuts the volume, must be something to do with t...

Hi Jarrod, Regards the 6n8 cap setting. Bare in mind C103 (1nF) rips of a massive amount of bass on the standard circuit,, as you do need to wipe a lot of lows when using heavy dirt,,,but if you lower C112 the bass loss is now way too much so if you raise C103 up to ~10nF that may help to balance th...

Maybe check your pins are correct against the data sheet,, as they are different to LM78xx series.
Great playing BTW and yeah,, close enough I'd stop tweaking for more top end as that will likely make it worse .
Phil.

Hey Jarrod, Just my observations,, Change C112 from 12n down to 2n2 or similar that will flatten the mid hump. Don't try grabbing more top end in this circuit,, You would be far better off hanging a tone stack on the end. Also I agree with Mr BMXguitar the compressor is likely not that great so inse...

I just did a quick sim of the response curves from R112A.
C112 (12nF) gives the mid hump,, lower values will flatten that out if needed.
Phil.

Perhaps I am getting ahead of myself but..... maybe good to add some control of the compression (which I always thought was rather high in the Rockman), would adding a pot like this (see red outline in schema) adjust the speed/attack of the compressor? And, if we wanted to add a threshold pot? Wher...

Regards this; Still has splatty distortion when cranked, but I've learned enough recently from my experiments on the Traynor (and Merlin's excellent book), that this is easily overcome with making good choices in the preamp. With no grid stoppers it's a fair bet it will splatt I'd be inserting Grid ...

what makes amps sound so incredibly different? what makes a mesa break up so starkly differently from a fender? Simple answer, Extra gain stages. (as mentioned) It's a common Q, What's the "main" difference between Marshall and Fender amps? I would Answer, Power Valves first. Just reading...

If the the unmentioned problem is not related to this part and there is no evidence of overheating and the amp has been running for years like that,, then it's fine. 3Watt is a common value at that point as it's only driving the preamps. 10k,,12k nah close enough for a guitar amp,,,leave it,, you wi...

Interesting quirk, Eons ago I built something similar. Sort of a loadbox come attenuator / line out. I rectified the signal to drive a fan and have never noticed the symptoms you describe. I used a full wave bridge and cap to store some energy,, maybe that helps? If you want I can pop the lid, Circu...

LessLee update; Removed C12, C17 & R19. (Was no need for the Caps) Added R26 4k7 across VR2. Max resistance is now ~3k. Unlikely to find a 3k pot so a 10k with 4k7 gives a good balance. R23 up to 47k. (needed to reduce clock noise bleed through) Note Q1 supply must be taken before R25 otherwise ...