Polytone MiniBrute II assistance needed!

[Le Basseur]

Got this li'l freak on repair.Symptoms:
1.The original loudspeker is missing (some cheap OEM instead).
2.The reverb doesn't work properly,as the reverb pot is turned clockwise there's an increasing "shhhh" noise coming out.However,the reverb tank is intact (just measured it).
3.The owner complaints that the amp is heating excessively.I ran it on the bench on moderate volume without the back pannel and nothing of the sort.I didn't get out yet the driver/output stage circuit as it's placed on the bottom of the combo and I hate touching that mineral wool inside the box but I saw two big,old electrolytics in a very poor state (surely,amongst others,this amp needs a full recap job as all the electrolytics are "originals").
And now,the issues:
1.The front pannel logo says "Mini-Brute II" but the back pannel plate says "model Mini/Teeny Brute 90 Watts Serial No. P-6202".What model am I dealing with?
2.No matter what about the above,I did find some Polytone schemos here:
http://www.murchmusic.com/polytoneserviceinfo.htm
but nothing looks like the amp I have on the bench.The most confusing thing is that on the schemos I see 4558s,071,LM358 and 301 IC's but on the amps' PCB there are (from left to right) LM301,LM1303N,LM301,TBA231,TBA231.
Does anybody have a valid schematic for this amp?I'm kinda lost,please help!
3.What might be the most appropriate replacement driver for this amp,assuming that the owner wants to keep "that specific Polytone's voicing"?
There are some rumours that the original,4 Ohms' Polytone's driver is (or was,for that instance) some kind of Eminence.Any thoughts?
Thank you!
Regards,

[Enzo]

I have some older schematics, not sure how well they will scan. Have you contacted Polytone and asked?

http://www.polytoneamps.com/

All the drivers I have seen in them have been Eminence. I think of these in terms of PA systems. Like a keyboard amp, so a full range speaker rather than a guitar speaker.

I don't have a problem with the insulation, it hasn't got into my skin so far. But some disposable plastic or rubber gloves would work.

[Le Basseur]

Hey Enzo,
Thanks for your comments!

Have you contacted Polytone and asked?
http://www.polytoneamps.com/

No chance.They have no e-mail address and a phone call is out of question from where I live due to outrageous local fees.
Besides,I read some Polytone users' comments about the poor customers' service over the phone (something related to an old lady/secretary unwilling to cooperate)...not necessary true,but I'm not in the mood to spend big $$ on a trans-oceanic phone call just to get some evasive reply.

I have some older schematics, not sure how well they will scan.

If I'm not asking too much and when you got some time for it,please try scanning those schemos and post them somewhere (or send them by mail)...TIA!

All the drivers I have seen in them have been Eminence. I think of these in terms of PA systems. Like a keyboard amp, so a full range speaker rather than a guitar speaker.

Very useful info,thank you!

I don't have a problem with the insulation, it hasn't got into my skin so far. But some disposable plastic or rubber gloves would work.

I'm some kind of a "Terminator" myself (I have very resistant hands' skin on a wide variety of textures and chemicals,with no side effects whatsoever)...but not on the mineral wool,wich gives me some noticeable irritation.Wearing rubber gloves does solve this problem but I'm kinda "old school",always prefer working with bare hands.
Regards,

[DCRon]

Any luck with your reverb ssssh issue (#2)? I've got the same thing...THANKS!

[Zfatweasel]

schematics for minibrute: Polytone Mine-Brute problem - diyAudio

[pipposalsiccia]

I have some older schematics, not sure how well they will scan. Have you contacted Polytone and asked?

http://www.polytoneamps.com/

All the drivers I have seen in them have been Eminence. I think of these in terms of PA systems. Like a keyboard amp, so a full range speaker rather than a guitar speaker.

I don't have a problem with the insulation, it hasn't got into my skin so far. But some disposable plastic or rubber gloves would work.

hi Enzo
I have a poly mini brute ii from 1980.
I noticed a distortion at the tail end of notes (not all notes but mostly trebles)
what’s your opinion about it?
I noticed also there’s some rattling from the brite normal dark switch. I positioned it in between brite and normal and the rattle magically disappears.
regards

[Enzo]

Hard to say from here. My first thought is rubbing voice coil on the speaker.

If a panel switch is loose and mechanically noisy, replace it.