Single Rectifier Series 2 tighter gain mods?

[Slayer5150]

Hi there, g'day from sunny Perth Australia.

I am a noob so please go easy.

I have read and seen vids on Single Rectifier Series 2 tighter gain mods.

I have looked and read etc... But does anyone have a schematic of how to achieve this or a step by step guide... I know I must be missing something when I search.

Thanks,

Paul.

 

[Slayer5150]

I'll add, it's hard down here to get mods done hence the question. Any help would be great!

Thanks again Paul

 

[meesa_jarjar]

do you have links to any specific posts or vids where people describe the mods?

 

[Slayer5150]

There are a heaps.. Mainly demos... No actual instructions or visuals I can see what they do to make the gain tighter.

This is for a dual rec... He says made one mod... Doesn't say what it is... The discord link doesn't work anymore... What is it!?



Or this one

Pre 500 mod

 

[Slayer5150]

Well no tech willing to Mods here will do anything it seems without schematics of the mods... If anyone has them.. please help a brother out!

 

[Slayer5150]

I ended up getting the change needed for the Aggro modded recto... If anyone is interested PM me.

 

[RDTech]

Ah mate, I’ve been super busy to check on my socials. Just catching up. Sent you the discord link. Looks like you found what you needed but still happy to help.

 

[Slayer5150]

Yep, I got the link mate, thanks so much mate, single recto is with my tech as we speak.

What exactly does this one mod do to the very untrained?

 

[RDTech]

It’s actually pretty simple, after the first gain stage there’s usually a 0.02 capacitor. Buy changing that to a 0.002 we’re taking off way more low end before it hits the next gain stage. This makes it so much tighter. I also means we can turn the bass control up to compensate without it loosing its aggression

 

[Slayer5150]

Thanks mate. What about changing the gain pot to a higher rates one... I have heard people doing that too?

 

[RDTech]

I didn’t feel it was necessary to be honest. Just that one mod did what I thought the amp needed. Always make one change at a time

 

[Slayer5150]

Noted... I have asked for a 500k gain pot... I need a new pot in any case as the current one is broken in half... That's it. And a service as it's a recent secondhand purchase . He knows not to change any tubes etc if they are good... He's a great honest bloke.

Looking forward to hearing the end results!

 

[Slayer5150]

Hey @RDTech I have messaged you on your discord channel a question if you don't mind?

 

[Slayer5150]

Okay I'll just put my question on here and see and tech knowledgeable peeps can help...

My tech is doing the cap mod for my Single Rectifier... Now under the hood... It appears that perhaps the previous owner has swapped the clean channel (bottom pot far right) to a 1meg and the top pot which is for the dirty channel (top far right) has been left as 250k... Do you think someone has tried to mod this themselves and stuffed it up?

Also, are the capacitor values for each pot correct?

I actually want this the other way around haha. 1 meg for the dirty channel so need to know if the capacitor values are correctly mounted...

Anyone? Fire away

 

[bjosephs]

It appears that perhaps the previous owner has swapped the clean channel (bottom pot far right) to a 1meg and the top pot which is for the dirty channel (top far right) has been left as 250k... Do you think someone has tried to mod this themselves and stuffed it up?

The single rectifier series 2 schematic I have show that this as the stock potentiometer values. 1 Meg for clean, 250k for dirty. I haven’t looked at the gain pots on mine but this seems right to me.

Also, are the capacitor values for each pot correct?

I don’t think those caps are the ones that get modded.

I actually want this the other way around haha. 1 meg for the dirty channel so need to know if the capacitor values are correctly mounted...

Anyone? Fire away

If you are trying to tighten the amp by reducing the coupling cap values, increasing the potentiometer value will have the opposite effect. Both the cap and the resistance it passes signal to affect the cutoff frequency. The higher the frequency the tighter the amp.

 

[Slayer5150]

Thanks for the response.

The mod I am actually aiming to do is the one RDTech has show in his Aggro modded mesa vid on YouTube. That's all good and I know the mod.

It was more the gain pots... I am not not having the coupling caps modded. I thought all of the gain pots were 250k.. in any case I think I have it sorted. I do want the dirty channel to be a 1 meg pot... Ensuring the 102k is going to the OD gain pot.

 

[meesa_jarjar]

Thanks for the response.

The mod I am actually aiming to do is the one RDTech has show in his Aggro modded mesa vid on YouTube. That's all good and I know the mod.

It was more the gain pots... I am not not having the coupling caps modded. I thought all of the gain pots were 250k.. in any case I think I have it sorted. I do want the dirty channel to be a 1 meg pot... Ensuring the 102k is going to the OD gain pot.

There is a coupling cap and 2 bright caps in the lead gain circuit feeding into and paralleling the gain pot, I would recommend changing those accordingly if you like the overall freq response of the gain. if you don't change them, it will add more low mids and bass. that isn't a bad thing of course but if the goal is to increase tightness then more bass up front isn't typically how you would go about it. if the mod schem you have doesn't change the caps then ignore my suggestion.

 

[gymbo2012]

I didn’t feel it was necessary to be honest. Just that one mod did what I thought the amp needed. Always make one change at a time

Thanks for the response.

The mod I am actually aiming to do is the one RDTech has show in his Aggro modded mesa vid on YouTube. That's all good and I know the mod.

It was more the gain pots... I am not not having the coupling caps modded. I thought all of the gain pots were 250k.. in any case I think I have it sorted. I do want the dirty channel to be a 1 meg pot... Ensuring the 102k is going to the OD gain pot.

It’s actually pretty simple, after the first gain stage there’s usually a 0.02 capacitor. Buy changing that to a 0.002 we’re taking off way more low end before it hits the next gain stage. This makes it so much tighter. I also means we can turn the bass control up to compensate without it loosing its aggression

Would it be possible to circle the 0.02 cap that needs changed to the .002 in a photo of the board? I can't seem to locate it. Thanks. JR