Brown Note Forum

[dcribbs1412]

anyone know of a layout for a 3way choke/sag standby switch?

[Tone_Merc]

I'm mobile right now, but I believe I posted a diagram in the gallery under my BM100 build.

[dcribbs1412]

thanks Tone_Merc
I didn't see a diagram
but I see a gut shot of your switch (nice build BTW)
I think I can figure out someway to do it.
any shots of the finished amp?
do you use the switch much?
are the differences noticeable?
sorry for all the ?'s
I'm thinking about diving into a 100w
not sure of hrm or not
again thanks for your time
D

[Tone_Merc]

[Shawnee]

Do you mount it between the power tansformer and the output transformer right under the power supply board? Would it be OK to mount a separate switch next to the choke underneath the chassis? (I don't think it would be something that I would change on the fly). Will it change any voltages that would have to be corrected by switching between the choke and the 500 ohm resistor?

[Tone_Merc]

I used a standby switch configured as on/off/on. Yes, voltages will change.

[Shawnee]

Thanks Tone-Merc. I may just start with the resistor and modify after I get this thing working!

[Shawnee]

Sorry for more questions but:
Is the choke impedence 100 ohms? If so, don't you have to use a 100 ohm resistor also to be able to switch between the two and still have correct voltages?

[Tone_Merc]

A choke's primary property in inductance, which is measured in Henries. It also has DC resistance, which of course in measured in Ohms.

I used a Fender Twin style choke which is typically around 4H and 100 ohms.

I guess you could match them, but I think it would negate the intent of introducing some screen sag into the power supply circuit.

I had all the parts in front of me so it was a painless mod to try. If I could do it all over again, I would just stick with a choke.

[Shawnee]

Thanks Tone_Merc- from what I have read, everyone who has tried the choke liked it more than the resistor. I may just use the choke from the start. Since I don't have a choke already, what would you recommend? How do I figure out what to change in the dropping string to get the voltages right?

Thank you for consistantly answering my questions. I haven't gotten very many responses from other folks since I started posting. I'm not a bad guy......really.

[Structo]

I put a choke into my D'Lite 44.

I used this one.

http://www.tubesandmore.com/scripts/foxweb.dll/moreinfo@d:/dfs/elevclients/cemirror/ELEVATOR.FXP?item=P-C194B

http://www.tubesandmore.com/

Here is a layout I altered.

I also changed the standby switch so the first filters are charged when the power switch is flipped but the high voltage to the rest is after the standby.
There are also a couple other mods on this layout.
The PI trimmer is nice, allows you to adjust the balance of the PI.
The local NFB switch is cool, switching it off makes the amp a bit looser/ raw.

Then there is the midcap switch, this switches between a .01uF and .06uF.
It is labeled FAT and THIN.
I use the FAT setting for single coils and the THIN setting for humbuckers.
I also moved the overdrive trimmer to the back panel so I can adjust that.

This is the Tweaked Layout that incorporates a bunch of mods from the Amp Garage.

As far as the dropping string, change the 220K on the end of the string to 150K. That is the FET simulator resistor.
All tubes and amps are different so you can't say change this resistor for this voltage.

But, in the end, the most important mod you can do to these amps is the voltage to the plates.
I can't stress that enough, the voltages play a huge part in the tone of these amps, so before you mod anything else get these voltages inline and then play the amp for at least 20-30 hours before considering changing values of other components.

I forgot to ask you but, what power tubes are you using?
6V6? 6L6?

The stock D'Lite was designed around 6V6 tubes so if that is what you are using then stick with the stock values on your amp.

Try for 200v on V1, 200-210v on V2 and 290-300v on V3.

It's been a while since I was inside my amp but I believe I have the same dropping string as this layout shows, and my amp has the choke.

[Shawnee]

Thank you very much. Great info Tom! (not that I totaly understand all of it ) I have the transformers that can run 6V6's or 6L6's. I will start with 6V6's and probably not change that although I wired the switch to do either. If I get my volatges right for 6V6's and switched to 6L6's, would the dropping string need to be changed even if I re-bias?