C+ pream differeces.. shot

[merendina]

Hi Guys,

The first pics is my simul 100w and the second my C + AB coliseum..

There is two arrows to indicate the difference between the two heads.

Why they use a cap into the coliseum board??

 

[Boogiebabies]

It's the .001 bright reduction cap on the second lead drive stage. It is standard on 60/100's but is deleted on Simul's.
I am more interested in that giant 3KV cap off the mid pot.
Is your mid pot on the non simul a pull switch ? If you could, can you tell the value on the cap ?

 

[merendina]

It's the .001 bright reduction cap on the second lead drive stage. It is standard on 60/100's but is deleted on Simul's.
I am more interested in that giant 3KV cap off the mid pot.
Is your mid pot on the non simul a pull switch ? If you could, can you tell the value on the cap ?

Hi BB,
yes, i have a push pull in the mid knob.
When i bought the head the seller told me that was a MKIII Coliseum but the serial shown a MKIIC+. Probably was confused by the push pull.

I think was a custom order prior the MKIII because it works in the same way to my hears.

When i engage the clean, i can pull the knob and you can hear a nice smooth crunch..

Are these the original solderings??

Look at this Pic with the cap's specs

 

[mrd]

Those are some nice photos... makes me wish I knew what all that stuff does so I could tinker with it a bit :lol:

 

[stomper]

Those are some nice photos... makes me wish I knew what all that stuff does so I could tinker with it a bit :lol:

Check your local community college. I learned antique radio repair first. Then got into building pedals, and repairing amps. I haven't paid a tech in 14 years. Class cost me $75 and about double that in some good tools.

 

[Boogiebabies]

It really looks stock. Would you mind telling me what the value of the caps is at the end of the 150pf. It has a purple top.

This my be where Mesa figured out where to put the R2 gain boost for the MK III. It could have started out as a mod. This is very interesting.

 

[merendina]

It really looks stock. Would you mind telling me what the value of the caps is at the end of the 150pf. It has a purple top.

This my be where Mesa figured out where to put the R2 gain boost for the MK III. It could have started out as a mod. This is very interesting.

BB,

It's a 22K 3KV

David

 

[Boogiebabies]

La protezione in cui avete la protezione viola su un 60/100 è normalmente 10pf/10K e 20pf/20K su un Simul-Class categoria. Your' la s è soltanto un po'più alto un poco più luminoso, ma quando aggiungete 22pf e 150pf paralelamente ottenete 172pf che è approssimativamente lo stesso 180pf usato per il R2 sul Mk III. Come il Mk III, una volta agganciato con il modo del cavo dovrebbe aggiungere un po'più guadagno.



Normally the cap where you have the purple cap on a 60/100 is 10pf/10K and 20pf/20K on a Simul-Class. Your's is only slightly higher an a bit brighter, but when you add 22pf and 150pf in parallel you get 172pf which is roughly the same 180pf used for the R2 on the MK III. Like the MK III, when engaged with the lead mode it should add a bit more gain.

 

[merendina]

La protezione in cui avete la protezione viola su un 60/100 è normalmente 10pf/10K e 20pf/20K su un Simul-Class categoria. Your' la s è soltanto un po'più alto un poco più luminoso, ma quando aggiungete 22pf e 150pf paralelamente ottenete 172pf che è approssimativamente lo stesso 180pf usato per il R2 sul Mk III. Come il Mk III, una volta agganciato con il modo del cavo dovrebbe aggiungere un po'più guadagno.



Normally the cap where you have the purple cap on a 60/100 is 10pf/10K and 20pf/20K on a Simul-Class. Your's is only slightly higher an a bit brighter, but when you add 22pf and 150pf in parallel you get 172pf which is roughly the same 180pf used for the R2 on the MK III. Like the MK III, when engaged with the lead mode it should add a bit more gain.

Wow Ed! thanks for your translation in Italian.. I think you can open an italian school in US if you bore with amplifiers :lol: :lol:

 

[Boogiebabies]

After another look, it's the exact same way the MK III gets it's R2 boost.

 

[Boogiebabies]

After another look, it's the exact same way the MK III gets it's R2 boost.