What are your favourite tube screamer mods?

[HamishR]

I'm not a fan of the TS but it can be made to sound ok. The tone control is over-complex and not particularly effective. Just ask Chuck! You don't really need the transistor stages and it's surprising even to me how much better a regular TS sounds with a bass control. The main thing I would always change though is the diodes. A single pair of 1N4148s or 1N914s is always going to sound naff. Try a pair of BAT41s, red LEDs or a quad of the regular diodes and it will feel a lot less plastic. Getting rid of the little cap over pins 1 & 2 can really help it to sound more natural, especially if you're using it more as a cleanish boost.

 

[music6000]

A stock Tube screamer circuit with LED clipping, no clipping, standard clipping with a Bass control!:

 

[cdwillis]

I prefer an extra diode for asymmetrical clipping like the SD-1 or four diodes for a little less compressed and buzzy sound. LEDs are another good sub like someone already said.

 

[Nostradoomus]

 

[Aentons]

View attachment 65484

If I ever call anything trash, my 12yo son instantly turns to me and says "You're trash!"

 

[HamishR]

FWIW the Rockett Touch is a TS with LEDs as clipping diodes.

 

[neiltheseal]

So I finally got the time to put a rough draft of a schematic together.

If anyone wants to have a look at it and see if it all makes sense that would be great. In particular the charge pump. Ideally I'd like to go from 9v to 18v and have this as an external switch. Can I use a SPDT per my schematic or do I need to use a DPDT.

I am ideally going for a stock Tubescreamer, but with the ability to add as many mods as possible. I still want to be able to revert to stock if I feel like it. As an explanation of what I have put together, I stole the schematic from the little green scream machine from Robert here. I also added the following:

• Charge pump to run at 9v/18v
• Switch to go from TS9 to 808
• Switch to remove input and output buffer
• A boost that I can toggle on and off with a footswitch
• Order switch to make boost before or after the TS
• Mids control from frost drive/ST9
• Toggle to remove mids control
• Locut from frost drive
• Brightness pot. I got the idea from Aion FX who have a bright toggle switch. I wanted more variety so I have 2 caps in parallell and a pot to vary between them. The karma sutre/anthithesis fuzz has this and I quite like it.
• Gain 1p8t switch per the Palisades/stockade drive
• Bandwith 1p8t switch per the Palisades/stockade drive

I think I really over-engineered this one. I think it's going to be massive.

 

[jimilee]

So I finally got the time to put a rough draft of a schematic together.

If anyone wants to have a look at it and see if it all makes sense that would be great. In particular the charge pump. Ideally I'd like to go from 9v to 18v and have this as an external switch. Can I use a SPDT per my schematic or do I need to use a DPDT.

I am ideally going for a stock Tubescreamer, but with the ability to add as many mods as possible. I still want to be able to revert to stock if I feel like it. As an explanation of what I have put together, I stole the schematic from the little green scream machine from Robert here. I also added the following:

• Charge pump to run at 9v/18v
• Switch to go from TS9 to 808
• Switch to remove input and output buffer
• A boost that I can toggle on and off with a footswitch
• Order switch to make boost before or after the TS
• Mids control from frost drive/ST9
• Toggle to remove mids control
• Locut from frost drive
• Brightness pot. I got the idea from Aion FX who have a bright toggle switch. I wanted more variety so I have 2 caps in parallell and a pot to vary between them. The karma sutre/anthithesis fuzz has this and I quite like it.
• Gain 1p8t switch per the Palisades/stockade drive
• Bandwith 1p8t switch per the Palisades/stockade drive

I think I really over-engineered this one. I think it's going to be massive.

View attachment 66931

That looks very cool. When it comes to symmetrical and asymmetrical (2, 3 and 4 of the same diode), I don’t think k you’ll hear a whole lot of difference in your clipping diode variations other than more compression. I could be wrong, though.

 

[Robert]

Pin 8 is VCC for the charge pump. As drawn it will never receive power.

You probably want to keep pins 1 and 8 connected constantly then use the switch to take power from the cathode of D1 (9V) or D6 (18V).

 

[cdwillis]

Your mids control isn't going to work if the buffer isn't on because the positive pin isn't biased without the buffer.

 

[neiltheseal]

Pin 8 is VCC for the charge pump. As drawn it will never receive power.

You probably want to keep pins 1 and 8 connected constantly then use the switch to take power from the cathode of D1 (9V) or D6 (18V).

Thanks. I knew this didn’t look right but couldn’t figure out how to do it.

 

[neiltheseal]

That looks very cool. When it comes to symmetrical and asymmetrical (2, 3 and 4 of the same diode), I don’t think k you’ll hear a whole lot of difference in your clipping diode variations other than more compression. I could be wrong, though.

You are probably right. I’ll have to have a think about what I want here.

 

[neiltheseal]

Thanks

Your mids control isn't going to work if the buffer isn't on because the positive pin isn't biased without the buffer.

thanks. Good eye.

If I put a connection to vref here going to pin 5 when the buffer is off, so you think that will work?

 

[cdwillis]

Now that I'm looking again I would put a resistor on pin 5 from vref. You'd still need it even if the buffer wasn't bypassed. There's more tweaking to be considered. If the buffer is bypassed you have the 1uf cap going to the 1k resistor and the 10kc low cut control which is probably going to load the signal a ton and just a 10k resistor to bias the positive pin afterwards. If you increase the 10k to 1m it would probably help with the impedance, but the point of bypassing the buffer I assume is to have that lowered impedance that interacts more with the guitar. I'm no EE, just a hobbiest lol, so take whatever I find with a grain of salt. I'm not sure how that low cut control is going to interact in that portion of the circuit depending on the buffer and mid being switched on or off.

 

[Brett]

I'm not sure if this is intentional or not, but based on your switching scheme (SW2), it appears that you'll never be able to bypass the circuit.

Edit to add that SW1.2 is wrong. If you flip the switch, you're disconnecting the circuit.

Editing a second time to say that your boost circuit is non-functional as drawn. Q3 requires power.

 

[neiltheseal]

I'm not sure if this is intentional or not, but based on your switching scheme (SW2), it appears that you'll never be able to bypass the circuit.

Edit to add that SW1.2 is wrong. If you flip the switch, you're disconnecting the circuit.

Editing a second time to say that your boost circuit is non-functional as drawn. Q3 requires power.

Thanks for the reply.

Yes SW2 is wrong. Robert has suggested something that I will try.

You are completey right about SW1.2! I think I have fixed that now.

Thanks RE the boost. I can't believe I forgot the power.

 

[neiltheseal]

Thanks for the comments everyone. I knew I had missed a few things but I'm glad you could all go over this for me. I know I would have been troubleshooting this for a while.

So how does this look?

1. - I think the power is connected properly allowing me to switch from 9v to 18v.
2. - Mids opamp (IC2.2) now has power from vref and a 220k resistor connected to pin 5. I got the 220k from AIonFX Cirrus.
3. - The 10k resistor after the mids/locut now has a 1m trimpot to allow me to adjust this if necessary.
4. - Boost circuit now has power
5. - SW1.2 now (I think) does not disconnect the circuit and instead switches from buffered output to non buffered.

My real goal with this is just experimentation. I'm not good with breadboards so want to be able to toggle things on the fly to see what I like. I have no real design idea other than that. I want to be able to compare a stock TS and see what each change does.

 

[Brett]

Yes SW2 is wrong. Robert has suggested something that I will try.

I'm wasn't referring to the switch in the power section.

 

[Brett]

To add to my previous comment, your schematic around SW2 shows TS In. I assume that this net label should be connected to the net of R1 (going into the TS section). If so, and this switch is going to be mounted on the same board as the rest of the circuit, I think the net labels need to match.

 

[neiltheseal]

To add to my previous comment, your schematic around SW2 shows TS In. I assume that this net label should be connected to the net of R1 (going into the TS section). If so, and this switch is going to be mounted on the same board as the rest of the circuit, I think the net labels need to match.

You mean I won't ever be able to turn the circuit off?

Yes I need some attention to that. However my idea is to make this effectively two independent PCBs but on the same board. I'll just connect everything with wires.

Had trouble getting my head around the order switching.