Royal - Fresh Man Tube Amp

Ultra 61?

I'm not sure I want to make a high gain amp or not. I'm thinking two channel amp with tremolo and reverb with a 15" speaker if I can squeeze one in (haven't really checked for that yet). OR, possible a kind of Laney clone/copy of some sort. See what happens.

P.S. I just realized I'm going to have a cool old school gold Peavey emblem to put on the wall - cooooollllllllllll............
 
Being I started this thread for those who may come across a Royal - Fresh Man amp...

So, BACK TO THE ROYAL FRESH MAN amp or I was anyways...

After playing it several times and all being well I played it one last time before stuffing the chassis back into the cab. Wouldn't you know it the harley potato potato was back. So, I opened it back up and found a resistor that had one of it's leads about ready to fall off the resistor body - I replaced it. The potato potato was more faint, but still there. There wasn't any way I believed it was filtering at this point being it was being over filtered at the moment in my opinion (but, it originally got rid of the potato potato). So, looked for a pesky intermittent oscillation. It seems that the feed to the reverb input tube is prone to oscillation, at least in this amp (V1A pin 2). Used a 0.0047 cap to ground to remove it completely (any less and it started rearing it's head, any more, well, no need). This was the only location I found that removed the oscillation.

So, figured time to remove (if possible) some of the seemingly over filtering used to originally remove the potato potato. I was able to remove the 10uf input capacitor for the 6x4 rectifier, but removing the 10uf cap I added for the two 12ax7's started introducing a sputter again - so, I left the extra 10uf filter cap in and removed the 10uf input capacitor.

The amp is now nice and quiet, reverb works well - it's not as boingy or over kill with the 0.0047 cap but is still very single spring piezo reverb tank sounding - I'd say more usable really.

I've attached the a schematic to show the recent changes...

Hope this thread may help another amp fiddler that comes across what seems to be the rare Royal - Fresh Man amp...

Time to move on,
Enjoy, enjoy...

P.S. this amp has a 10" speaker in it - not sure where how I got 12" speaker on the brain, but... ya... life goes on - lol...
 

Attachments

Couple last pictures. Finally buttoned it all up. This shows how I went about adding a power cord restraint and speaker wire restraint. You can't see the speaker wire restraint real good, but it's being held on by a speaker nut.

Buttoned back up (3).jpg

Buttoned back up (5).jpg

After buttoning it up and playing it I can say it's a joy to play and vibe on. The reverb and tremolo on this little amp play well together and provide a spacious pump vibe to the guitar. If you find one, give it a shot - cool little amp for sure...
 
@Drumoid
I really like how nice and illustrated your drawn schematics are. Very clear and detailed, and very professional. Yup, I just touched myself again... :cautious:

Can you look at the following schematic, for one of my amps, and suggest where the optimum location would be for current limiter thermistor?
Chihuahua 6V6 Schematic.jpg

Right now, the thermistor is connected between the fuse and the PT's BLACK wire
 
@Drumoid
I really like how nice and illustrated your drawn schematics are. Very clear and detailed, and very professional. Yup, I just touched myself again... :cautious:

Can you look at the following schematic, for one of my amps, and suggest where the optimum location would be for current limiter thermistor?
View attachment 44100

Right now, the thermistor is connected between the fuse and the PT's BLACK wire

Optimal ?

We'll, no matter how I answer that question someone will be sure to disagree and have a different preference - lol - and not that I'd really disagree with their disagreement/preference if that makes sense - lol...

I appreciate your having the confidence in me to answer this, but... I'd prefer not to answer ;)

But, again, thanks for deeming me worthy to ask a question like this...


edit: P.S. Hey, Ivan H - you'da'man - what say ye ??? Seriously, you do very well explaining things in words...
 
I appreciate your having the confidence in me to answer this, but... I'd prefer not to answer ;)
Anybody here is welcome to share their knowledge on this, but you seem to be the only one with actual 'thermistor' experience. Therefore I'll rephrase my earlier question... Is my location of the thermistor as I suggested earlier, OK?

The way I have that thermistor set up, it will always have AC current going through it if the AC cable is plugged into a live AC socket regardless whether the amp's power switch is on or off. But if I were to connect the thermistor between the power switch and the AC cable's or the PT's WHITE wire, then the thermistor will have current only when the power switch is on. Is this correct? Does it make any difference?
 
It's were I'd put it in an amp with the fuse and switch wired as above...

I like thermistors for dropping the incoming juice a bit. I'm working on restoring and old Hammond AO44 reverb amp at the moment and according to the schematics it's looking for 117Vac for the incoming juice to the primary of the power transformer - so, I'll be sticking a thermistor on it.

However, using them for inrush current limiters, for amps that use diode rectification for example, you have to be careful that dropping the Vac on the PT primary doesn't drop the voltage too much on the secondary feeding your rectifier, etc. But... then again... a perm brown sound may be the cats meow for the amp too - lol and ;)
 
Anybody here is welcome to share their knowledge on this, but you seem to be the only one with actual 'thermistor' experience. Therefore I'll rephrase my earlier question... Is my location of the thermistor as I suggested earlier, OK?

The way I have that thermistor set up, it will always have AC current going through it if the AC cable is plugged into a live AC socket regardless whether the amp's power switch is on or off. But if I were to connect the thermistor between the power switch and the AC cable's or the PT's WHITE wire, then the thermistor will have current only when the power switch is on. Is this correct? Does it make any difference?

If you think about it - the black hot wire is hooked to the fuse - the fuse is hooked to the primary side of the transformer on one side, which is a coil of wire that connects to the switch on the other side (that the AC goes thru), that connects to the white neutral wire. With the switch open the black/white wire is an open loop, with the switch closed it is a closed loop - for lack of better words.

But, I hesitate to say which is better as either side you put it on there will be people who agree and disagree or say it doesn't matter, which is why I generally just repair/build/mod stuff and stay out of the talk/advice side - plus, I suck at talking and social stuff - lol...
 
However, using them for inrush current limiters, for amps that use diode rectification for example, you have to be careful that dropping the Vac on the PT primary doesn't drop the voltage too much on the secondary feeding your rectifier, etc. But... then again... a perm brown sound may be the cats meow for the amp too - lol and ;)
But, I hesitate to say which is better as either side you put it on there will be people who agree and disagree or say it doesn't matter, which is why I generally just repair/build/mod stuff and stay out of the talk/advice side - plus, I suck at talking and social stuff - lol...
All of your points are well taken and thank you very much... :cheers:

FWIW...: The 'CL-60' thermistor in my 2204/50watt/EL34's will drop the incoming AC (on the average...) by 1.5 volts. Amp's B+ will drop close to 10 volts. Heaters will drop about .05 volts per side
 
I don't do well looking over peoples shoulders or vice versa - never have I guess. HOWEVER, If you and I were close by, hanging in person, etc and messing with stuff it'd be a whole different story - now that, I enjoy ;)
 
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