D'Lite mid control and extra cap

[phsyconoodler]

I was wondering about the Revised D'Lite layout with the 250k mid pot and the extra cap and 10meg resistor.I installed the mid pot without the extra cap and resistor and it is more than a pleasant surprise.The mids jump out on a very musical way now.I was just wondering what the purpose of the cap from the 100k resistor to the preamp trimmer pot does,and also the 10meg resistor?

[kleinm]

I was wondering about the Revised D'Lite layout with the 250k mid pot and the extra cap and 10meg resistor.I installed the mid pot without the extra cap and resistor and it is more than a pleasant surprise.The mids jump out on a very musical way now.I was just wondering what the purpose of the cap from the 100k resistor to the preamp trimmer pot does,and also the 10meg resistor?

The additional 0.05uF cap trims more bass going into the overdrive portion.

The the 250kA is part of the change from the stock D'Lite to the Skyliner setup - the 0.01uF mid cap and 330pF treble caps round it out.

The purpose of the 10M resistor on the 0.05uF cap's input prevents popping during channel switching as it provides a ground reference. 10M prevents any untoward EQ shaping.

As for the cap from the 100K resistor to the OD trimmer, I have no idea what you're talking about?

[Structo]

I think he is talking about the OD entrance mod.
100k referring to the OD trim.

[kleinm]

Structo, could be, but it sounds to me like the 100k and trimmer are two separate things?

...the 100k resistor to the preamp trimmer pot...

[Structo]

Hmmm, unless he is referring to the 100K tail on the V2a plate.
I guess I should stop guessing.....

[phalanges]

"The additional 0.05uF cap trims more bass going into the overdrive portion."

Would a smaller value cap, ie, 0.02uF, trim more, or less bass?
Thanks.

[greiswig]

"The additional 0.05uF cap trims more bass going into the overdrive portion."

Would a smaller value cap, ie, 0.02uF, trim more, or less bass?
Thanks.

The cap is acting as a high-pass filter, so a smaller cap cuts off at a higher frequency. Also, keep in mind that this is in series with another cap in the circuit. The "magic" pairing seems to be a .05uF (stock in D'Lite) in series with an added .02uF cap. If you have already replaced the stock cap with a .02uF and that still isn't enough bass lost, then adding a .05uF is a good place to start.

[Pete]

I think of it this way: In the spectrum of tone from low to high you are passing the frequencies from the top most to some point in the middle.
A larger cap lowers that point a smaller cap raises it. So, yes you would get less bass with a smaller cap. (large enough value passes everything of course) HTH

"The additional 0.05uF cap trims more bass going into the overdrive portion."

Would a smaller value cap, ie, 0.02uF, trim more, or less bass?
Thanks.

[phalanges]

Thanks, guys.
I think I'll go back to the stock value on the V1b coupler.
I've added the pre OD 0.05uF w/ 10M to ground and it's a slight bit more nasal sounding.

[phsyconoodler]

Thanks for the explanation guys.
I ended up going back to the stock configuration because when the mids were turned down it got nasally as described.I had just the opposite thing going on when the overdrive was engaged.It got trebly.
I switched back and the extra treble was less pronounced.This is at lower volumes,at higher volumes it's pretty awesome sounding.
I also notice that the stock 2k presence pot doesn't bleed off enough treble for my tastes.I use a 5k as a result.It's range is narrow but I rather like the treble cut.I also tried the original Dumble presence wiring with no connection to the end lug on the presence pot,and promptly went back to the D'Lite way.For this particular amp it works better.
It seems a few changes from one amp to the next and a speaker change requires quite a bit of tweaking to get it right.It's interesting what different speakers do to this amp.I'm trying an Eminence Govnor and it's an interesting tone.Some tones are less than pleasant but if you work with it and change your attack on the guitar it gets very pleasant sounding.Unfortunately it requires too much EQ to get it to sound good both clean and distorted.I guess 'good' is relative,I'm trying to compare it to my first choice in speakers,the Greenback.The greenback kills the eminence but lacks the power handling.Guess it's time for a G12-65!

[Ed de Jager]

I am a bit confused about the term mids.What are mids,frequency wise?
My amp(Dlite with bluesmaster PI,skyliner tonestack) is sounding great with EL34`s and a 15 inch speaker but i would like a bit more in the 180-380 Herz area.What mod would get me a bit in that direction?
A mid-boost?Or is that treble?
Thanks in advance,Ed

[dogears]

Try increasing NFB. What tap are you on? Try the 8 ohm tap. Or try using a 68K feedback resistor instead of the 100K. That will tighten things and for me gave the appearence of more of a pleasing low end.

I am a bit confused about the term mids.What are mids,frequency wise?
My amp(Dlite with bluesmaster PI,skyliner tonestack) is sounding great with EL34`s and a 15 inch speaker but i would like a bit more in the 180-380 Herz area.What mod would get me a bit in that direction?
A mid-boost?Or is that treble?
Thanks in advance,Ed

[Structo]

I believe the D'Lite uses a 6K2 NFB resistor.
At least that is what mine has.
Scott I thought before you recommended a 4K7 there?
Or are we talking about two different things.

[Ed de Jager]

I am on the 8 Ohm tab(transformer only has an 8 ohm tab)I`ll give that 68K a try first thing tomorrow morning but i`m still confused.
180-380 herz is low?Where does the mids begin then?
Structo;this Dlite has the bluesmaster PI.
Thanks again,Ed

[Structo]

OK, so which resistor are we talking about?