Kev's "Cobble Together a Good 3000 PL Preamp" thread...

[Gepetto]

Going to hook you up soon, Kev!!!

Hey Joe for 12 volt relays with a 17 volt supply, what current limit resistance should be used? Got em in, now time to put 'em in!

With 17V, that would be 120 ohm, 1/2W Jer.

 

[jbeckva]

Will 100 ohm do in a pinch, or too much current?

 

[Gepetto]

Will 100 ohm do in a pinch, or too much current?

It will do in a pinch Jer. Get the right ones eventually but that will get you going.

 

[jbeckva]

Thanks Joe! Will do that and perform relay "elimination" per Kev's needs! Seriously .. I'm listening to Steve Morse with my own (same amp section) right now!

Powerful man.. LME49740'S.. Great choice if you have a need.

 

[jbeckva]

Just had a killer idea pop in...

So the relays leaving in will be three of them. Two inputs, need to go to proc out on common/NO contacts. One for the output, straight from proc in. So instead of jumpering ANY relay that would be jumpered on both ends, Looking to use the shielded cable for all runs, which will be minimal.

eh??

 

[CASSETTE DECK]

I've noticed a lot of variation in the resistance of 12 volt relay coils.

 

[jbeckva]

Blue Jams

Some Friday nights are better than others!

<iframe width="640" height="360" src="//www.youtube.com/embed/B93pxQQEpeQ?feature=player_detailpage" frameborder="0" allowfullscreen></iframe>

 

[kevin]

Going to hook you up soon, Kev!!!

Hey Joe for 12 volt relays with a 17 volt supply, what current limit resistance should be used? Got em in, now time to put 'em in!

Sounding good Jer !!!! Hey.. Did ya get what i sent you ? Never sent any like that... Hope I did that right ?

 

[jbeckva]

Grrrr

Still pluggin away at this PITA.. Thought I had 'er, but hmm... developed a buzz. PS may be suspect in this chassis...

SO....

Here we go again LOL... "Numero Three-O"... Gotta rob all the good new caps and put 'em in, retweak the 20 volts back to 16 or so, and see how it goes... Relays in this bassid are also as flakey as a ... errr... apple turnover?? (lol)...

 

[laatsch55]

Hell, there's only 6 left to replace!!

 

[jbeckva]

Hell, there's only 6 left to replace!!

6 what??

 

[jbeckva]

Aint replacing but 3 relays, but there's 16 caps to do.. no matter, I'll get r done on this round!

 

[laatsch55]

6 what??

6 relays, then you'll be done..

 

[jbeckva]

6 relays, then you'll be done..

I might just do 3... or I might wire 'em all up (but whaddapain heheh).

Stripped all the nasty old things off, and transplanted the new caps... Might have 'er back together and testing by tomorrow night...

 

[laatsch55]

Got some TIS 93's and 97'ss in there or are those the 35somethings..?

 

[jbeckva]

Got some TIS 93's and 97'ss in there or are those the 35somethings..?

Yep, I see a few TIS's there - those are the relay current sinks.

Hey.. look carefully... on the bottom right look at the cluster of 4 caps with two DIP-8's on either side. Look at those two resistors that look "new", but you can see they both burnt up at one time with the discoloration around 'em. Hmm.. that's the headphone amp, I believe. Better test it out if Kev is going to use a pair of cans..

 

[laatsch55]

I see that on some of the 3300's too Jer...

 

[jbeckva]

I see that on some of the 3300's too Jer...

Headphone amps that went "blooey"??? Dang.. both sets of those resistors smoked (look up around the other side). I guess someone was trying to mach 8 themselves with a pair of cans.. hehe.

Welp, good nuff for tonight. Gotta do up the power supply tomorrow, plus get some solid small awg wire to "properly" dead-bug those new relays and whatnot. Got a debate going on with myself tho... do I do all relays? Hmmm... one thing I did notice on the last round was it would SEEM that the heat sink on the regulator IC's was getting a bit hot, and if I recall right that was with just a couple installed. Do you or Joe have the coil current spec for the originals?? I would like to compare it to these 12 volt guys I have...

 

[laatsch55]

No, I don't have Jer...

 

[Gepetto]

Headphone amps that went "blooey"??? Dang.. both sets of those resistors smoked (look up around the other side). I guess someone was trying to mach 8 themselves with a pair of cans.. hehe.

Welp, good nuff for tonight. Gotta do up the power supply tomorrow, plus get some solid small awg wire to "properly" dead-bug those new relays and whatnot. Got a debate going on with myself tho... do I do all relays? Hmmm... one thing I did notice on the last round was it would SEEM that the heat sink on the regulator IC's was getting a bit hot, and if I recall right that was with just a couple installed. Do you or Joe have the coil current spec for the originals?? I would like to compare it to these 12 volt guys I have...

Measure one with an ohm meter Jer