1482Esq

[sluckey]

Two things...

The 1M resistor under the speed pot should be 100K.

A 12AU7 does not have enough gain to work in this circuit. Change to 12AX7, or, if you want to keep the low gain 12AU7 in the cathodyne position, change to a 12DW7 tube. That way you have a low gain triode for the cathodyne and a high gain triode for the oscillator.

[shooter]

I can just swap the AX from V2 into V3 and make V2 an AU for now, slipping the decimal also 
thanks
dave

[shooter]

alive, still waiting for the posthuman to do Her part, email says by Friday

[sluckey]

So you not gonna perform a photocell-otomy on that Fender roach? Real easy to put it back together if it doesn't act like you want. That photocell ain't picky about where it's light comes from. Marry it to your red LED while waiting for the postman. There was another forum member that successfully did this for the TON.

[shooter]

photocell-otomy on that Fender roach

I'm assuming it's fine, I just used it wrong.
gonna re-do DV and AC bench checks since I got 10hrs on the tubes and I noted Bias drifted up.

Something I should know but.....

Since I'm self biased PP A1, am I "ok" running close/over to max diss, instead of the "60%" fixed guideline 

[sluckey]

Yes, most all cat biased amps run 90-110%.

[shooter]

thanks, I was wobbly on PP 
It's too nice a day to be inside and Pam's home wounded from moving the large among us
so the amp might get a couple days rest 

[shooter]

I'm such an addict 

9 gator-clips, 2 ecaps and 2 meters, don't get any better 
Thanks DL, I put 100uf at tap A and another at tap D, tamed the ripple so I'm happy.  I was never "out of spec", but the "swing" was end-to-end of my "spec"
now the fluke gets bored
~ 7.8mV AC at tap D, ~ 2V at tap A.
so caps on order, threw in 2 1X/10X reasonable priced scope probes since I only have 1 left +HV probe

the snow blower did make it to it's summer home 

[PRR]

> the snow blower did make it to it's summer home

I did that, and now it snows every day.

Enough for kids to make snowmen.

Mostly melts by noon.

[shooter]

now it snows every day.

ya, had that last week, last gasp winter, Every spring indicator is here now sans swallows and hummingbirds, but they always sleep in 

[shooter]

found 10minutes and put in the roach, results not good.  well marked so got the LED in correct.  here's a scope shot from top of LED, I was on the 20mV scale 1X and it's to low for the digital to guess at values.  Freq setting about where I expected.

since I got way more IC opto's than i'll ever use now, might BB up one on a battery n experiment but got life getting in the way for the next day or so.

[sluckey]

Use your 87V to check the AC voltage and frequency at the plate of the oscillator tube. First set the freq to 5Hz with the speed pot. Then check the AC_rms voltage. Should be about 100VAC_rms. What have you?

[shooter]

with fluke;
5.38hz (range ~3hz - 17hz)
Min 70vac
max 76 vac
avg 73vac

[sluckey]

And what is the dc voltage on the cathode of the tube?

[shooter]

with roach, 1.46, when I had the redled, was 1.65

[sluckey]

Is your roach a VTL5C1?

One more check with the 87V... Disconnect the VTL5C1 from the INT pot. Measure resistance of the VTL5C1 dangling leg and chassis. It will be changing so set the speed pot to slow and use the MIN-MAX feature on the meter. What have you? Only interested in min/max numbers.

[shooter]

Is your roach

yep, antique radio, NOS

max 2.7M (drifts UP, about 1once in 30 seconds by 10K or so, 1st Max was ~1.6M)

Min 72k

NOTE:
after ~ 8minutes, quit ranging and settled at 3.4M  Min stayed happy

[sluckey]

Everything appears to be working. Now use a gator clip and connect the dangling leg of the VTL5C1 DIRECTLY to the circuit as indicated in this pic (not using the INT pot yet. You do have the two caps in place, right? Report back.

DO NOT CONNECT THE VTL5C1 TO ANY DC VOLTAGE!!!

If you don't get a strong trem effect then move the gator clip to V2 pin 2. Report back.

[shooter]

held my hand all the way! 
trem is strong, freq varies, swamp works.

probably bad shielded cable.  I'm out for the afternoon mostly, thanks.

Nother oddity NFB, was playing with it earlier, with the 39k engaged, I get a "cleaner, small gain boost" and sounds nice, when the 680 ohm engaged, screams

[sluckey]

OK. Now connect the VTL5C1 back to the wiper of the INT pot and connect the top of the INT pot to the circuit. Ground the bottom of the INT pot. What have you?

[shooter]

I'm beginning to think this amp is cursed

 

ok, here's my testing;

Wired per snippit;
No guitar sound

.4ohm from injection point to ground
Verified cable and pot good disconnected from circuit
Wired back up, same  .4ohm
Installed new pot, same
Resistor side of opto infinity to ground
Original pot 100kRa
2nd pot 500kL
Disconnected, guitar sounds
Opto jumpered as before works as before

Oddity;
No power, in circuit, pot disconnected from incretion point, connected to opto and ground;
pot read 0-120k – 0, out of circuit 0 – 500k

who needs an int pot 

[shooter]

3rd pot's a charm!
first 2 were new, Cmade, test good outta circuit.

I have a 1M L beat up radioshack, works fine in circuit, but only from ~.9M to 1M
anything less and trem either quits, or guitar just overwhelms it.

It's time for some AMERICAN HOMEGROWN POTentiometer   

[shooter]

did a AC trace for some wonky, but not bad sounds, found problem, not resolving tonight 
big wave is plate of cathodyne, small input.
Big R's in morning 

[shooter]

Waiting for the Sun I went back and looked;
when I went to AX in the PI I had girlfriend looking wave, now, gramma looking.
The only changes;
1k under cathode of PI, and cut input cap feeding PI from .01uF to .005uF
anyone got a sense about that before I try n "fix" something that wasn't broke 

[sluckey]

What's the status of the tremolo?

[shooter]

I have a 1M L beat up radioshack, works fine in circuit, but only from ~.9M to 1M anything less and trem either quits, or guitar just overwhelms it.

This "tells me"  any "loading" messes with signal/trem, passed my paygrade to get if it's an impedance thing, insertion location,.......

It does work as expected, just over a very short range

(the resistance I'm quoting is from insertion to ground, measured no power after I played and found the pots range)

[shooter]

clarified gibberish;
pots 1 & 2 and shielded wire removed, verified outside circuit to be good.  There had to be a fail somewhere that I missed.

Pot 3 1M l measures consistent .98M to ground at insertion point.
Pot3 wiper to ground;
at .98M, strong trem, strong guitar
at .91M, no trem (sound), strong guitar

[sluckey]

Disconnect the INT pot. Use a gator clip to connect a 47K from ground to the insertion point. Do you still have enough guitar signal to be useful? If so, use a 50K pot.

[shooter]

connect a 47K from ground to the insertion point

that's where I was heading next.

Gave up on "why", added 10_edit_K Gstoppers to the PA tubes, added a 470k Gstopper into PI.  (Thanks DL:)

signal path is as good as it's gonna get.  The gain pots need tweaking since range for "good signal" 0 - 5, past 5 things distort up in a not so good sound.  Difference at speaker power wise is minimal

pic 1 after Gstoppers
Pic 2 max clean PI in, Speaker out
pic 3 Max usable, same points as pic 2

[shooter]

still have enough guitar signal to be useful

here's the data;
Baseline, nothing at insertion point to ground, (all #'s Vacrms)
in 38.6 out 39
470K to ground
38.5  39
100K to ground
38.3 38.3  (starting to "load" signal, slight distortion top n bottom lobes)
56k to ground
36.8  35.4 (heavier "loading" on lobes)

[sluckey]

OK. Leave the 56K connected and also connect the opto dangling leg to the insertion point. This is the same as having a 50K int pot set to max. How is the trem effect? Put your scope down and plug in a guitar. I want to know what your ears think.

[shooter]

was doing this when you called; 

hunted down a 100k, verified, installed, and I got 1K to ground at insertion 

roach reads 1K to ground 

powered up, roach danced the fluke, but only "around" 1K 

Never been much of a quitter, but this might be a good time to practice 

[sluckey]

How the hell do you put a 100K between the insertion point that I suggested and ground and then measure 1K. Not likely in my world.

I ask for a 47K to ground but you show me a bunch of data using various resistors, one being 56K. OK, that's pretty close to 47K. Then I ask for you to leave the 56K in and also connect the opto to the insertion point. But you connect a 100K!!! We sure ain't communicating.

Show me some pics of this amp! No scope traces please.

[shooter]

I ask for a 47K to ground

we're on the same page,
I wanted to know what NO trem value was, 1st measure.
Since I had 1M pot that worked, I started there  and went backward to 47K. (56k, called that one close and quit looking)
The problem is the roach resistance keeps changing.
last night I played, it trem'd like I expected with the 1M pot.


The roach ohmed infinite 2 or 3 times during testing
The roach ohmed 1K 2 times during testing
EVERY time I ohmed the roach the "wiper" wire was disconnected, amp off.

I have 2 NEW roaches and 3 NEW pots on order.

we can both use the break while parts are coming 
If the roach is supposed to be 1k to ground, or it's irrelevant then I'm game for whatever.

[sluckey]

You've proven that the TON circuit is functioning. Now all you gotta do is experiment to find the right interface. Just keep experimenting, you'll get it.

Here's a variation of the interface that a guy over on TAG used. His trem sounds phenomenal.

[shooter]

Just keep experimenting

once I learned to solder, I learnt 60hz was audible and I had a power cord and speaker 

[sluckey]

Any progress?

[shooter]

 
No parts yet, but I'm playing better.
This thing is really a nice one for noodling on, fixed the NFB, just subtle differences to me, same with the tone knobs, but I'm not a knob fiddler.

The Gov won't let me n my brother fish in the same boat, so getting parts past the check points might be iffy   

[DummyLoad]

The Gov won't let me n my brother fish in the same boat...

i thought alcohol kills corona?? if that's true, i don't see how that's an issue as long as you're getting seriously hammered when you're fishing. did i miss something?

--pete

[shooter]

did i miss something?

You'll need ALOT to understand this edict!
"No more than 2 related persons per boat, same address"
I don't live with my brother so I get thrown overboard 

[shooter]

new roach in, trem works as designed, but INT pot (100k) is only good from 7-10.

so gonna re-wire like the bandmaster final with the 10k cathode R and FS toggling the LED, and a 50K int and evaluate.

but I smoked my brakes NOT smoking a dog, so 2 blown lines and a complete bleed-down and it's back to early march temps 

[shooter]

Buick on hold so I soldered up the Proper parts and it Trems well, good range, nice sounds for a hack wanna-be.  marking up the schematic, callin it DONE 

[Platefire]

Whew! Ya'll was wearing me out Glad that's solved. I know what it feels like to want to give up on something but it's quite a victory once you get there. Ya Haw!!!

[shooter]

Ya'll was wearing me out

I'm already washed up, worn out, but I can still crawl 

[sluckey]

i thought alcohol kills corona??

I have a bottle of corona dope. Unfortunately it dried up several years ago.   

[shooter]

 
was cleaning up random junk in the barn, found a jar of instant coffee from the '90s, paused while I though, hmm If the world melts....  Pitched it.
Found a random baggie, probably the same time-frame, laughed since I can buy that as  essential product 

[PRR]

> corona dope. Unfortunately it dried up several years ago.

Just the solvent/spirit. Try a cocktail like this:

Toluene 108-88-3 70.0 %
Ethyl Alcohol Denatured 64-17-5 10.0 %
2-Butanone (MEK) 78-93-3 5.0 %
Methyl Isobutyl Ketone 108-10-1 5.0 %

[shooter]

ok, pleading ignorance, I had lots of corona balls in my equipment, but never cleaned with corona dope, just alcohol 

[sluckey]

Silly you. Corona dope ain't for cleaning. 

[shooter]

ok, sent the ducks, they got confused!
guessing it's the "finger nail polish" for coating wires, not the dielectric grease I put on the anode/cathode of X-ray tubes before seating them?  that was pure HiVolt silicon
didn't even bother with guitar cleaning product link