bright switch on a SFPR.Want less bright cap-Values??

[billyz]

I have experimented with Parallel caps. But, not on the Bright cap or treble response cap. Parallel caps are additive in capacitance. At those positions you are lowering the affected frequency. I usually want to raise them . IE replace the 120 pf with 47pf. If you parallel a 47pf poly with a ceramic 47pf you get 94pf. The difference in tonality between a Polystyrene and Ceramic at those frequencies is not huge, it is subtle though.

To sum it all up.
1.Different type cap changes the nature of the tone.
2. Different value cap changes the frequency response.
3. Adding a trimmer in series changes the level of the signal and maybe a small change in frequency response.

Also, I have experimented with using a Larger value cap in those positons. IE 500pf, passes more frequencies and can be useful as well. More of a boost effect with high frequency emphasis.

Honestly for my money, I like the treble cap to be Polystyrene. Really smooths out the highs. Ceramics can ring, which is sounds irritating to me.

[Colossal]

I have experimented with Parallel caps. But, not on the Bright cap or treble response cap. Parallel caps are additive in capacitance.

Sorry, I meant paralleling much *lower* values, say 2x22pF to get 44.

To sum it all up.
1.Different type cap changes the nature of the tone.
2. Different value cap changes the frequency response.
3. Adding a trimmer in series changes the level of the signal and maybe a small change in frequency response.

Also, I have experimented with using a Larger value cap in those positons. IE 500pf, passes more frequencies and can be useful as well. More of a boost effect with high frequency emphasis.

I've seen high value bright caps on the D-style schematics. I was interested in paralleling caps of differing values to get the harshness out but retain the highs to a certain extent. Perhaps going with say 2x47pF and then using a trimmer in front of it would afford the most flexibility(?)

Honestly for my money, I like the treble cap to be Polystyrene. Really smooths out the highs. Ceramics can ring, which is sounds irritating to me.

This is good to know and I am going to give it a shot. Thanks for the idea. I am really looking to afford the harsh, brittle, ear-fatiguing bite but attain more of a "CD-quality" kind of high (if you follow me) where the highs are there but with the edge taken off. Not CD-quality in terms of digital sparseness, just clean and articulate without the shrill. Hard to put this stuff into words but hopefully you get my meaning.

I appreciate your comments.

[sidehatch]

I did all the mods as outlined by heisthl and chaned the tones stack from .1,.047 and 250pf to a .047 orange drop, .022 paper in oil sprague and a 330pf silver mica.

I changed the highlighted caps to .047 orange drops and the red cap to a .003 like Heisthl recommended.

Much better but still too bassy.

Well,


I pulled out the cannabis rex and put in a G12H30 70th anniversary.

Fixed!!! Its that C-rex. At this point I can only recommend those for amps that are shrill. If it was a stock late 70's pro reverb that is usually too bright it would be great but I already had this amp BF'd and slightly modded.

I'm going to gig it tonight and see how i like the RW&B/ G12H30 combo.

I also have a G1265 incoming I can try

[Structo]

Did the speaker switch tame the bass?

If not try either a bigger slope like a 150R.

Or try a smaller coupling cap on V1.

[sidehatch]

Im all set up on this amp now.

I dont think a pro reverb could sound better. I love the tone and think the clean tone is now up there with my Carr/redplate hybrid.

I changed the bright cap to a silver mica 48 pf. Lovely to me. Subtle but nice!

Just adds a teeny bit of sheen instead of the ice pic.

After trying many speakers I settled on a Weber 1265 and a emi R,W,&B combo. I liked it better than the G12h30 and the C rex and some Jensen c12,weber 12f150 and a few others. the G12h30 found its home in my 62 Gibson falcon Ga19rvt