Old tubes, New pedal?

[matopotato]

Transforming an old radio/78rpm record player into a cabinet left a few part over.
Would any of these tubes be useful for a pedal project? Pre-amp/OD?



Telefunken AZ 41 (B0202809)
Miniwatt EAF 42
Marconi Meck 42
SER 6J6
SER 6AQ5 (two of them)

[amptramp]

AZ41 is a low current fullwave rectifier suitable for a 60 mA output.  The cathode is directly heated.  The heater is 4.0 volts @ 0.72 amps.

EAF42 is a single diode + remote cutoff pentode that could be usable for a compressor since the remote cutoff provides different gain at different bias points.

No idea what the Marconi MECK 42 is.

6J6 is a twin triode with a common cathode often used for RF oscillator-mixers.  It would be good for a long-tailed inverter for audio.

6AQ5 is a beam power output tube originally designed for car radios with 6V6 characteristics but reduced power output, usually limited to 10 watts for a push-pull pair.

Be aware that the first three tubes are rimlock designs with a European-only 8-pin socket, so keep the sockets.  You have the makings of a nice amp here.

[printer2]

Tubes are cheap, the transformers, not so much, they are the important part. What was the make and model of the radio?

[matopotato]

Tubes are cheap, the transformers, not so much, they are the important part. What was the make and model of the radio?

Radiola, by LM Ericsson.
Any transformers are already sent to recycling center. Sorry.

[GibsonGM]

Any transformers are already sent to recycling center. Sorry.

Oh, you should be...   

[matopotato]

.... but... but...
They were huge... and dirty...
Hard to see how how they could have been used in a pedal...

A rat had been housing in it. Some ripped newspaper to make cosy and a couple of spare ribs dragged in from trash can probably. Well gnawed.

So Ideally the tubes would be used in  a tube based RAT. Somehow...

[mozz]

Ahhh, I see a nice output transformer right there. Oh too late, in the landfill. 

[PRR]

Any radio/phono is already 9/10 of a kitchen-size guitar amplifier. Just fiddle the preamp to suit guitar.

That was a pretty deluxe radio. Two 6AQ5 is 8 or so Watts and the P-P transformer can have bass without so much cost, and "big amp" breakup.

That's not a lot of mouse poop to vacuum-up.

Tubes in a pedal is very awkward. They melt your shoes (HOT!!). They rattle when you tap them. They break when you kick them.

[davent]

Have built a couple single ended amps using the 6aq5 and one push pull using a pair.

[printer2]

.... but... but...
They were huge... and dirty...
Hard to see how how they could have been used in a pedal...

A rat had been housing in it. Some ripped newspaper to make cosy and a couple of spare ribs dragged in from trash can probably. Well gnawed.

So Ideally the tubes would be used in  a tube based RAT. Somehow...

Not for a pedal but an amp. Dirty?



Rodent litter?



I salvaged the output transformer and the speakers (why they never touched them?), chewed through insulation, this one I wore a N-95 mask when I started to take it apart. It is a shame you did not salvage the transformers, that looks like it would have made a decent amp by someone. No, the tubes would not be much use in a pedal.

[GibsonGM]

A rat had been housing in it. Some ripped newspaper to make cosy and a couple of spare ribs dragged in from trash can probably. Well gnawed.

Do you still have the ribs?   

[printer2]

A rat had been housing in it. Some ripped newspaper to make cosy and a couple of spare ribs dragged in from trash can probably. Well gnawed.

Do you still have the ribs?   

[matopotato]

A rat had been housing in it. Some ripped newspaper to make cosy and a couple of spare ribs dragged in from trash can probably. Well gnawed.

Do you still have the ribs?   

Nope, they went out with the transformer.
Sorted in different bins of course.
(We do separate Plastic, paper, foodstuff, glass, ribs, metal, transformers, cardboard and wood)

[matopotato]

Ahhh, I see a nice output transformer right there. Oh too late, in the landfill. 

Top picture middle or the far right?

[matopotato]

Any radio/phono is already 9/10 of a kitchen-size guitar amplifier. Just fiddle the preamp to suit guitar.

That was a pretty deluxe radio. Two 6AQ5 is 8 or so Watts and the P-P transformer can have bass without so much cost, and "big amp" breakup.

That's not a lot of mouse poop to vacuum-up.

I think it had the common sense not to litter in the bed/diner combo.

Tubes in a pedal is very awkward. They melt your shoes (HOT!!). They rattle when you tap them. They break when you kick them.

Yes, I was not planning on taking it on tour. Just seen a few around and thought since I salvaged the tubes maybe I could do something with them. I realize I should have save the transformer and sent it to whoever wanted to do something with it.

[matopotato]

.... but... but...
They were huge... and dirty...
Hard to see how how they could have been used in a pedal...

A rat had been housing in it. Some ripped newspaper to make cosy and a couple of spare ribs dragged in from trash can probably. Well gnawed.

So Ideally the tubes would be used in  a tube based RAT. Somehow...

Not for a pedal but an amp. Dirty?



Rodent litter?



I salvaged the output transformer and the speakers (why they never touched them?), chewed through insulation, this one I wore a N-95 mask when I started to take it apart. It is a shame you did not salvage the transformers, that looks like it would have made a decent amp by someone. No, the tubes would not be much use in a pedal.

You win the dust and the chewed paper shootout for sure.
I wish I had posted here before I began taking it apart.

[matopotato]

I guess the transformer is on its way to Nigeria or where EU ships "electronic waste".
Whenever I leave something at the recycling station I always wish the sorting guys would look away so I could do a quick dumpster dive and salvage what useful might be there. Besides germanium transistors I am now adding transformers to my dream.

[GibsonGM]

These things happen. I once had a B.K. Bulter tube overdrive, back in the 80s.  I couldn't get it to sound right (cough solid state amp cough).  So I smashed it to smithereens in the driveway.     What a jerk.

We didn't have Ebay, no way to really sell it, and nobody in my circle was interested.  Today, it's a popular OD (kind of like you want), and I could've used the parts inside.  Wasn't into electronics back then.    Live and learn!

I won't tell you what I did to my '77 Strat      

[merlinb]

Marconi Meck 42

That's an ECH42

These tubes aren't well suited to a pedal format, but you could stick them in a bigger box.
You can build a standalone preamp from most any triodes or pentodes (just triode connect the pentodes for simplicity). Slap them into a standard topology (e.g. gain stage > gain pot > gain stage > tone control > cathode follower buffer) with 100k anode resistors, tweak the bias resistors to taste, and you're done. It may never sound as good as a preamp build with ECC83s, but it will make sound.

[matopotato]

Marconi Meck 42

That's an ECH42

These tubes aren't well suited to a pedal format, but you could stick them in a bigger box.
You can build a standalone preamp from most any triodes or pentodes (just triode connect the pentodes for simplicity). Slap them into a standard topology (e.g. gain stage > gain pot > gain stage > tone control > cathode follower buffer) with 100k anode resistors, tweak the bias resistors to taste, and you're done. It may never sound as good as a preamp build with ECC83s, but it will make sound.

Thanks!