1973 Super Bass 100 - look OK?

[Quinny]

Hello all!

Wondering if the good folks here could cast their eyes over this '73 SB100 and let me know what you think in terms of originality/mids/issues etc? Common power cable mod done but looks very good on the whole to me. Would much appreciate the views and experience of those much more in the know.

Thanks!

 

[Crikey]

Hello all!

Wondering if the good folks here could cast their eyes over this '73 SB100 and let me know what you think in terms of originality/mids/issues etc? Common power cable mod done but looks very good on the whole to me. Would much appreciate the views and experience of those much more in the know.

Thanks!



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Looks mint from a non marshall tech view

 

[Ramhead]

That white head shell piping is not original, other than that looks pretty nice.

 

[TAZIN]

Interesting that the Tag sheet lists English Bass yet the circuit is a Lead therefore, I'd assume someone did a conversion. Overall it looks pretty good.

 

[Quinny]

That white head shell piping is not original, other than that looks pretty nice.

I've seen mention of a small number of 73s with white piping from the factory, not sure of numbers though (or even if it's true).

 

[Quinny]

Interesting that the Tag sheet lists English Bass yet the circuit is a Lead therefore, I'd assume someone did a conversion. Overall it looks pretty good.

So the fairly standard mod to tweak the stock Bass circuit to Lead?

 

[TAZIN]

So the fairly standard mod to tweak the stock Bass circuit to Lead?

Yes. A lot of Bass amps were modded to Lead specs over the years.

 

[Matthews Guitars]

Resistor across the presence pot, I've never noticed that before. A mod to change its range of operation, I imagine.

 

[neikeel]

You see a 4k7 across a 25k presence pot to eliminate the dc scratch
Bass converted to lead (and someone decided that they preferred 0.022uF on v1b coupler (messy solder).
Likely lots of low end.
I actually like this spec even though not stock
Esp with 6550s

 

[Quinny]

All easily reversible back to 100% stock should one be so inclined? Or, some original components no longer in place?

 

[TAZIN]

I assume this amp was originally setup/modified for 6550's since the bias splitting resistors are 82K's. As neikeel pointed out this amp does not have a full conversion to Lead specs...More of a mix between the two circuits. The output couple caps are still 0.1uF verse 0.022uF for Leads.

 

[Quinny]

I assume this amp was originally setup/modified for 6550's since the bias splitting resistors are 82K's. As neikeel pointed out this amp does not have a full conversion to Lead specs...More of a mix between the two circuits. The output couple caps are still 0.1uF verse 0.022uF for Leads.

Ah, that's good to hear! I looked at some other circuit pics earlier and came to conclusion it was some manner of semi-conversion, but had assumed I just didn't understand properly.

 

[TAZIN]

All easily reversible back to 100% stock should one be so inclined? Or, some original components no longer in place?

Yes, an easy amp to restore back to original specs. You'd need two resistors (56K and 820-ohm) along with a 250pF cap for the tonestack.

 

[Quinny]

Given the mods done and the partial kinda conversion between Bass and Lead, what impact do you think that would have on the tone of the amp? The full Bass to Lead tweak I'm loosely familiar with, but wonder what the intention was with the mods as they are...

 

[neikeel]

This spec is great for metal with humbuckers and ability to turn the wick up
We have a 71 this spec (plus a 2203 mode ) and it has great touch response and great lows esp in straight C or drop D.

 

[79 2203]

If you like playing a range of lower gain tones from amazing cleans and edge of breakup, Malcolm-ish bark to Kossof warm crunch, you can’t beat a stock Super Bass. My 70 is freakin amazing. Through a 68 straight with the original Pulsonic Greenbacks it reminds me of so many late 60’s/early 70’s sounds I grew up with.