thinking of dropping a switching relay in my KS marshall

[splatter]

The way its wired now is that one input runs to v1 and the other to v2 .I am thinking about dropping a switching relay in the signal path just after the input jacks . It seems to me if I interrupt the ckt before it hits the preamp tubes I should be able to make the BE and HBE switchable using just one input jack . Then use the other input for the footswitch .
Now its been years since I've worked in Electronics and I wasn't an engineer then so if my thinking is wrong let me know . I realize it may alter the tone but unless there is some other reason not to do it I'm gonna have to give it a try . Its easily reverseable so if it sucks up to much tone I can just take it out .
Thoughts ?

don't forget to stop by the proboards
http://friedmanfans.proboards.com/

 

[romanianreaper]

We need to get more people into the friedman boards man.

 

[splatter]

We need to get more people into the friedman boards man.

yea i know

 

[splatter]

so since no one is telling me not to do it I'm gonna give it a try . I will let you know how it turns out

 

[tonmazz]

so since no one is telling me not to do it I'm gonna give it a try . I will let you know how it turns out

Definately let us know, I am messing with some ideas on switching myself. What are you going to use to do it?

 

[splatter]

so since no one is telling me not to do it I'm gonna give it a try . I will let you know how it turns out

Definately let us know, I am messing with some ideas on switching myself. What are you going to use to do it?

I havent decided yet . Webber sells some pre made switching relays I was thinking about going with one of them , they even have an optical relay which should be dead quite ,but then I read something about how a jfet is perfect for switching so I don't know . My electronics days are way behind me and I think the jfet may require more knowledge than I retained . I need to sit down and draw out the schematic and to see if I can figure it out . But at this point I'm really leaning toward the webber relays .
I just bought a used slp reissue and should have it in a few days . I'm thinking of modding it and trying the switching relay in it first . Either way when I get it done I will be sure and let you know how it works .

 

[glip22]

The only negative I can see is that the relay may add noise. I'm not sure how you would ground it. You may have a very loud pop when switching if you do not ground it properly.

 

[tonmazz]

so since no one is telling me not to do it I'm gonna give it a try . I will let you know how it turns out

Definately let us know, I am messing with some ideas on switching myself. What are you going to use to do it?

I havent decided yet . Webber sells some pre made switching relays I was thinking about going with one of them , they even have an optical relay which should be dead quite ,but then I read something about how a jfet is perfect for switching so I don't know . My electronics days are way behind me and I think the jfet may require more knowledge than I retained . I need to sit down and draw out the schematic and to see if I can figure it out . But at this point I'm really leaning toward the webber relays .
I just bought a used slp reissue and should have it in a few days . I'm thinking of modding it and trying the switching relay in it first . Either way when I get it done I will be sure and let you know how it works .

Yes please do. I'm in the same boat, know enough to be dangerous and want to take it further.

 

[Blackie08]

Any updates guys???

 

[Greg Riley]

Why couldn't you just use a Lehle A/B with a quality relay already there? Like switching between 2 amps. Or the A/B/C if you using 2 amps and want control over the BE/HBE etc. I'm just guessing and curious to know if this does the trick.

 

[Blackie08]

Why couldn't you just use a Lehle A/B with a quality relay already there? Like switching between 2 amps. Or the A/B/C if you using 2 amps and want control over the BE/HBE etc. I'm just guessing and curious to know if this does the trick.

Because when using the BE or HBE the other input is defeated...

 

[CaseyCor]

I would think the added relay would affect your tone, and add a significant amount of noise. Maybe it would be a better idea to ask Dave how to get around the opposing input being defeated during use, and use an A/B box instead.

 

[Blackie08]

I would think the added relay would affect your tone, and add a significant amount of noise. Maybe it would be a better idea to ask Dave how to get around the opposing input being defeated during use, and use an A/B box instead.

You can't use an A/B box...

 

[splatter]

I would think the added relay would affect your tone, and add a significant amount of noise. Maybe it would be a better idea to ask Dave how to get around the opposing input being defeated during use, and use an A/B box instead.

You can't use an A/B box...

nope a/b box won't work .
THe relay should be here next week then we will see . It was pretty cheap and installing it should be a no brainer . If it doesn't work to my satisfaction I will just put the amp back the way it was and forget it.

 

[Greg Riley]

Why couldn't you just use a Lehle A/B with a quality relay already there? Like switching between 2 amps. Or the A/B/C if you using 2 amps and want control over the BE/HBE etc. I'm just guessing and curious to know if this does the trick.

Because when using the BE or HBE the other input is defeated...

I gotcha..

 

[LP Freak]

This sure is taking a long time.

 

[splatter]

This sure is taking a long time.

I didn't order the relay till last week on the 5th and you would think something as small as a relay they would drop it in a box and send it priority mail..... but no . They charged me $8 for shipping on a $12 part and apparently they are sending it via boat people express cause it isn't here yet. Also I'm in the middle of repairing a 76 jmp and this has taken precedence . However if I receive the relay this week I will try and install it over the weekend .I will let you guys know the results as soon as Its done .

 

[splatter]

I just got an email from fedex that weber finally shipped my relay . 6 days between payment and shipping is ridiculous imo . So I won't be getting it installed this weekend maybe next weekend

 

[splatter]

the part showed up on Saturday . I put it in the amp but I am having problems . The HBE needs the BE to run . I thought they were pretty much independent of each other but they aren't . I figured out how to make it work using a diode to separate them when on the BE side but when I switch to the BE I get a terrible ground hum . Not really sure why .
Im not done trying to figure it out but at this point its not looking to promising . I am not an amp tech so maybe some of you who know more about this stuff can chime in and give me some Ideas .

 

[glip22]

the part showed up on Saturday . I put it in the amp but I am having problems . The HBE needs the BE to run . I thought they were pretty much independent of each other but they aren't . I figured out how to make it work using a diode to separate them when on the BE side but when I switch to the BE I get a terrible ground hum . Not really sure why .
Im not done trying to figure it out but at this point its not looking to promising . I am not an amp tech so maybe some of you who know more about this stuff can chime in and give me some Ideas .

I don't think it will make a difference, but you can try to short the P,G, and K of the unused half of the HBE triode. Just use a piece of buss. When you first posted this my thoughts were that it was going to be tricky with grounding the switching relay. Where did you ground it to?