Nice Score at local Flea Market

[kagliostro]

Yesterday, with friends we went to a small electronics fair a few kilometers from home (20 minutes by road)

unfortunately it wasn't exactly interesting, very few participants and of these, only very few exhibitors of material that could have a little interest

So, at 11 in the morning we were home again

Since it was still early I decided to do one of my usual little trips to a local Flea Market near my house

I went in and.....









I know it has problems with the pot and Vibrato and Reverb didn't perform correctly

But 112.00 € for the Head and Speaker cab was so interesting that I got it

I was thinking that as it is an italian amp I must have to do some reverse engeenering to obtain the schematic but doing a search I was pleasantly surprised to find it as an old original (not very readable) and as a completely readable redrawn version 





Oh Happy Day 

Sometimes it doesn't take much to brighten up a day

 

Franco

[TIMBO]

SWEET!!!!!

[shooter]

nice score, now buy Valmer a espresso or 2 

[tdvt]

I was thinking that as it is an italian amp I must have to do some reverse engeenering to obtain the schematic but doing a search I was pleasantly surprised to find it as an old original (not very readable) and as a completely readable redrawn version 



 

Franco

 Nice find! Never heard of them.

Due to the name & faceplate labels, I initially I thought it was some regional US brand.

Was is customary to label things in English there?

[Glenn]

Nice find, I’m extremely jealous

[dogburn]

Nice! I bet it's loud when working properly. But I need to know what the "Bend" function is - never heard of an amp with that before.

[mresistor]

High DCV going through a phone jack?  wow   I don't think I've seen that before.

[PRR]

Interesting.

{ninja-ed by 10 minutes} Notice that there is 380 Volts on the loudspeaker jack terminals. When un-plugged, the B+ is disconnected, "standby". (But not if you unplug the cable from the speaker...) Be careful inside: we are not used to deadly voltages on speaker jack terminals. If that jack is replaced it has to be "special", or the standby function bypassed.

[PRR]

High DCV going through a phone jack?  wow   I don't think I've seen that before.

The Fender 300, I think, had three pairs of bottles and three speaker jacks. If un-jacked, that pair was disconnected, but at the cathodes (IIRC).

No, not the Fender 300. Maybe the first Ampeg SVT?

[sluckey]

The speaker jack is common. The Switchcraft 13 is such a jack. It has two isolated switch contacts. When the plug is inserted, the tip pushes against a nylon insulator that is attached to the movable switch contact and causes the two switch contacts to close.

A lot of amps found in '50s organs and juke boxes used the same idea but a round 4 pin socket/plug. The plug had a jumper across the B+ pins so when unplugged the B+ was interrupted.

[kagliostro]

Hi Friends

@ TIMBO, thanks

@ shooter, I've find the schematic in an old thread of 2010, I'm looking for ways to say thank you

@ tdvt, not always but it may happen that labels were in english to keep an international look

@ Glenn, may be next week also you find something of interesting, who can say ?

@ dogburn, also I'm intrigued from that Bend Function, I don't know exactly the purpose but I've found some guy that say that it is a Distortion Feature (I was thinking something like that because of the two diodes on the circuit), someone say they would want to emulate the fuzz machine Vox Tone Bender

@ mresistor, about the HV on the Phone Jack I think PRR & Sluckey clarified the situation, however I think I'll change that arrangement disconnecting that feature and inserting in the Phone Jack circuit a Dummy Load Resitor that will be connected if the plug is removed (like in a lot of amps)

Franco

[PRR]

Was is customary to label things in English there?

I know in Japan it was/is customary for domestic radios to be labeled in Japanese characters, and "professional" (High-Fidelity, Broadcast) audio gear marked in English. Obviously because US and UK builders filled the market first. Later local builders might use local language, or copy-cat the Big Builders. To look "classy", or to hope for International sales.

This one says "Volume" on front. On back "PU" is surely PickUp (phono), we see "635--1605 K.C.", but all the non-technical data is in Japanese characters.

[danhei]

The Fender 300, I think, had three pairs of bottles and three speaker jacks. If un-jacked, that pair was disconnected, but at the cathodes (IIRC).

No, not the Fender 300. Maybe the first Ampeg SVT?

The Fender 400 PS: https://el34world.com/charts/Schematics/files/Fender/Fender_400ps.pdf


Rich Koerner (RIP) has the most documentation on the amp that I’ve seen: http://www.timeelect.com/400-PS-IDX.htm

[Platefire]

I love a great search & find story. Congratulations! I will be interested to hear a report once you get it tuned up and running

[kagliostro]

A bit of Amp Porn









Franco

[TIMBO]

OOOOooooo Tidy.
Hmmmm hope there isn't a burnt resistor in there.

[sluckey]

OOOOooooo Tidy.
Hmmmm hope there isn't a burnt resistor in there.

Gonna be tough to work on for sure. Even a cap job will not be easy. Not made for the technician. Makes me appreciate the Fender layout.

[kagliostro]

.... Makes me appreciate the Fender layout. ...

Mee too 

However seems that here musicman like that model and it is appreciated and a bit valued

Franco

[danhei]

Can’t go wrong with four Siemens EL84s!

[shooter]

Not made for the technician

haven't met a Mechanical Engineer yet that took us poor field slobs into consideration.  did make it REAL clear in the paperwork why it took me 12 hours to do a 2 hour job, usually referenced the Mechanical Engineer by NAME
give 'em an education, they eat the crayons

[kagliostro]

You tempting me to dismant the PCB from chassis

then put sockets on the chassis, dismante the soclets that are on PCB

connect wires between PCB and sockets on chassis and mount the PCB on the chassis reversed

in the way youll see the components instead of tracks

Franco

[sluckey]

That's easy to say. Much harder to actually do. I suggest you ponder this idea some more.   

[kagliostro]

You tempting me ....

I wrote temping me, not convinced me 

Franco

[shooter]

once the tanks out of the way, that fine cable lacing is removed, you should have room to work.  Pick up some waxed string to re-lace once it's working well.  Patience is key, no double espresso's til AFTER it's up 

[Platefire]

Yeah a couple of those boards look really rough in some places but that don't mean their not close to working ok or not far from getting them up to par. I'd work on getting whats there going as is as shooter said, with much patients. It's a rare enough bird to warrant attempted life again:>)

[kagliostro]

Yes, sure, it must be restored, not reinvented


Franco