Choke + Sag Inducing Resistor Switch

mauiboy81 · Post by **mauiboy81** » Mon May 18, 2009 3:02 am

Hi guys,

I have a Heyboer 9H 120mA choke that I'm going to use in a 50W approximation of #124. I'd like to add a resistor that I can switch in and out to get a little sag.

The PT is 355-0-355 @ 300mA

Would a 100 Ohm 10 watt wirewound be sufficient or would i need to go higher on the power handling?

Would it be fine to have the resistor wired up for sag and then use the switch to jumper it for choke only?

I'd put the switch on the under side of the chassis so it couldn't accidentally be flipped with the power on.

Thanks

Nick

heisthl · Post by **heisthl** » Mon May 18, 2009 3:57 am

easier to just use a DPDT standby switch to pick one or the other:

mauiboy81 · Post by **mauiboy81** » Mon May 18, 2009 4:12 am

DPDT on-off-on?

In that case I would use something like 330 ohm resistor?

Have you tried it with choke + resistor or only one or the other?

With both in series you would get more filtering than with just a resistor but not as much voltage drop/sag, correct?

heisthl · Post by **heisthl** » Mon May 18, 2009 4:18 am

mauiboy81 wrote:DPDT on-off-on?

In that case I would use something like 330 ohm resistor?

Have you tried it with choke + resistor or only one or the other?

With both in series you would get more filtering than with just a resistor but not as much voltage drop/sag, correct?

Yes
yes
only one or the other
having the choke would pretty much negates the resistor because the main thing you are going for is the lack of the stored energy a choke provides.

Bob Simpson · Post by **Bob Simpson** » Mon May 18, 2009 4:33 pm

heisthl wrote:easier to just use a DPDT standby switch to pick one or the other:

I've seen several variations on this circuit, but never with all the caps.
Any particular rating required? Typical 600V?

heisthl · Post by **heisthl** » Mon May 18, 2009 5:57 pm

those are just the 1000kv disc caps for anti-arc and less pop any value in the .01 to .033 range works fine.

Bob Simpson · Post by **Bob Simpson** » Mon May 18, 2009 6:43 pm

heisthl wrote:those are just the 1000kv disc caps for anti-arc and less pop any value in the .01 to .033 range works fine.

1000kV?

ceramic caps?

I looked at your web site.
What are the 2 jacks on the lower panels of your heads?

TIA

Bob

heisthl · Post by **heisthl** » Mon May 18, 2009 7:01 pm

Bob Simpson wrote:
heisthl wrote:those are just the 1000kv disc caps for anti-arc and less pop any value in the .01 to .033 range works fine.
1000kV?

ceramic caps?

I looked at your web site.
What are the 2 jacks on the lower panels of your heads?

TIA

Bob

Yes 1000KV ceramic disc caps, the jacks are just a patch panel system (1/4 male - short cord- 2 females)for running 2 cabinets - useful for amps that don't have an impedance selector.

Bob Simpson · Post by **Bob Simpson** » Mon May 18, 2009 7:34 pm

Yes 1000KV ceramic disc caps, the jacks are just a patch panel system (1/4 male - short cord- 2 females)for running 2 cabinets - useful for amps that don't have an impedance selector.

I've searched mouser and digikey for 1000KV ceramic caps without finding any.
Do you have a reference number?

Thanks.

Bob Simpson

glasman · Post by **glasman** » Mon May 18, 2009 8:09 pm

Bob Simpson wrote:
Yes 1000KV ceramic disc caps, the jacks are just a patch panel system (1/4 male - short cord- 2 females)for running 2 cabinets - useful for amps that don't have an impedance selector.
I've searched mouser and digikey for 1000KV ceramic caps without finding any.
Do you have a reference number?

Thanks.

Bob Simpson

You sure those aren't 1KV caps. never seen an application that needed a 1,000,000 volt cap

.

Gary

Bob Simpson · Post by **Bob Simpson** » Mon May 18, 2009 8:30 pm

glasman wrote:
Bob Simpson wrote:
Yes 1000KV ceramic disc caps, the jacks are just a patch panel system (1/4 male - short cord- 2 females)for running 2 cabinets - useful for amps that don't have an impedance selector.
I've searched mouser and digikey for 1000KV ceramic caps without finding any.
Do you have a reference number?

Thanks.

Bob Simpson
You sure those aren't 1KV caps. never seen an application that needed a 1,000,000 volt cap .

Gary

Kind of what I was thinking, but I thought maybe I'd missed something...

Bob Simpson

heisthl · Post by **heisthl** » Mon May 18, 2009 8:37 pm

I'm a moron yes 1KV

glasman · Post by **glasman** » Mon May 18, 2009 8:49 pm

Thats what I'm talk'n bout.

Screw this 700W crap thats for beginers, lets go for some MegaVolts!!

I'm thinking a pair of 813's in PP mode with 2500 volts on the plates. Should be good for a few (hundred) watts

.

Actually the first "real amp" I ever built was in high school (A LONG time ago). A single 4-1000A with 3300 volts on the plates. Of course that was for RF service. But the 4-1000A makes a dandy modulator for an AM transmitter.

tictac · Post by **tictac** » Wed May 20, 2009 9:07 pm

Here's how I did it....

heisthl · Post by **heisthl** » Wed May 20, 2009 11:07 pm

tictac wrote:Here's how I did it....

How do you get power to the O.T. with that method? It would require a separate standby switch just to switch that.

Tube Amp Archive

Choke + Sag Inducing Resistor Switch

Choke + Sag Inducing Resistor Switch

Re: Choke + Sag Inducing Resistor Switch

Re: Choke + Sag Inducing Resistor Switch

Re: Choke + Sag Inducing Resistor Switch

What are all the .01 caps for?

Re: Choke + Sag Inducing Resistor Switch

Re: Choke + Sag Inducing Resistor Switch

Re: Choke + Sag Inducing Resistor Switch

Re: Choke + Sag Inducing Resistor Switch

Re: Choke + Sag Inducing Resistor Switch

Re: Choke + Sag Inducing Resistor Switch

Re: Choke + Sag Inducing Resistor Switch

Re: Choke + Sag Inducing Resistor Switch

Re: Choke + Sag Inducing Resistor Switch

Re: Choke + Sag Inducing Resistor Switch