For some stock shots first..
(Just a replaced resistor as the amp was DOA and i wanted to make sure it ran as supposed)
The reverb unit resides at the floor of the cab. Incl the reverb trafo. I recap,this is by far the best sounding spring reverb iīve ever encountered. IF it can be resurrected,just trust me...do so.
Itīll put the famed Fender reverbs to shame..
I modded this amp,and rather extensively to make it into an 18w dirty bluesrock screamer.
Word of notice. ALL,no exceptions,of the onboard capacitors-be it electrolytes or otherwise,NEEDS to be replaced. I donīt CARE if they "measure ok" cause if they havenīt sprung a leak at the moment...that moment will come soon enough. Iīve lost track of how many of the early ERA,WIMA,Siemens asf caps iīve replaced by now. They were most likely da bomb in the day,but 50 yrs later they are nothing but a menace. Replace every damn one of them if you value your life.
DIN jacks were tossed in the bin and got replaced by common teles. A masterpot,as you can see,got installed.
Cathode biased as you can gather,and rather cool at that. Measure what your specific amp wants and reset resistor value accordingly.
Thereīs no harm,on the contrary,in resetting cap value to either 47u or even 100u. Trafos will handle that.
This is the piggyback reverb PCB in OEM "unmolested" form. Ie;that is how it should look all said n done.
I went overkill for each and every one of the voltage droppin resistors. Capacitance was added in turn.
Sorry to say i never found an OEM schematic for the Hall-Jazz. The Jazz...no issues at all,thatīs to be found online and is readily available. Anyways...
I made this sucker into a 3 stage jobbie...and TBH in hindsight would i redo the whole thing today iīd opt to install yet a preamp flask and in turn remodel the PI into an LTP of Marshalleresk values. Altho the concertinas certainly can be tamed as far as their rather "jagged" behaviour,they IMO tend to be rather static once set. Sure...thereīs a number of solutions that adress that as well but when a LTP is that easy to setup...why bother.?
`N...for a meek 18watter the PI WILL come into play-like it or not.
The 3 stage jobbie tho...in hindsight..yeah..it turned out ok. Above fair iīd say. Not golden...but absolutely above fair.
If thereīs anything i can help you with as far as specifics,lemme know...