Mystery diode? (And a few other questions)

[dr.earlfunkton]

Hey yall!

I'm new to this forum so sorry if this isn't the right place for these questions.

      My current project is to use this old Bogen Challenger CHB-50 chassis as a donor to build a new front end and possibly new power section.
I figured I would keep the transformers and tube sockets but scrap everything else and build a fender style front end (Mix between BF Bassman and Deluxe Rev.).
While Im sure some of the components in this amp would be fine to keep, Id rather overhaul any part of the schematic that I decide to keep for longevity and reliability.
SO, I have a few questions regarding the amp. (Sorry if these are a bit obvious, im new to this hobby and have only been researching for about 2 months).
      1st: While looking at the power section, I was trying to find replacements for the SS rectifier diodes.
I believe I was able to find the diode labled "96-5109-01" but the only diode I could find for the "96-5036-01" seemed to be a fairly low voltage rating, at 35V, for being in a power section.
I marked the diodes in question in red on the schematic.
Anybody know where I can find replacements or at least data sheets for these diodes?
    2nd: While this amp seemed to be working (powered on) I didnt really have a way to test it as I dont have the weird mic connectors and the output jacks are some other obsolete connector.
Before I go gung ho on this thing, is there a way I can test the transformers before I build a whole amp around them as well as finding a data sheet for the transformers?
Could I also use the Voltage chart for the tubes to sort of reverse engineer/research to find replacement transformers if needed?
     3rd: I have a concept for making the tone stack switchable while utilizing the same pots.
Would it be possible to build a Fender tone stack as well as a Marshall tone stack using the same pots and a switch to choose between the sets of capacitor and resistor values?

Thanks in advance for any replies!

[ALBATROS1234]

i am new to tubes but it should be straight forward to test you transformer.simplest thing is to test continuity of the coils which if you dont know is measuring the resistance in ohms. primary tested to the other or any other primary wire will give you a reading in ohms.this is not 100% fool proof as if the transformer got overheated it could sometimes short out and still give you an ohms reading. the coil wires are enamel coated coper wire if the transformer overheats it can melt the enamel away and short windings to other windings. this could still give you a reading in ohms but the transformer will not work.

 the only fool prof way is if you test continuity you can at least figure out which wires go wire primary and/or secondary at this point you can apply voltage to the primary which can usually be traced to the input wires pretty directly. then you just test the secondary(s) and see what voltage you get. if it is a typical tube transformer you should have just 2 input/primary wires(unless its international in which case you could have 2 coils for primary and you can hook them up either series or parallel depending on if you want to run it 120vac or 240vac.) and usually a high voltage winding(usually w/ center tap) and at least one filament winding usually close to 6.3vac. but there could be a 5vac as well for the rectifier tube. that said it could also have a bias tap and/or multiple windings.... if its not hooked up so you cant see which side gets wall power you can put a low known ac voltage on it to figure out ratios i.e. if you put 10vac on a winding you have determined has continuity with ohm meter and you get 20vac out it is a 1 to 2 step up etc. i am obviously over simplifing to explain my point.

does this make sense?

[92Volts]

You shouldn't power on tube amps without a speaker (or dummy load) attached, it can damage the output transformer-- with that said, you likely didn't damage anything by doing it once, especially since you weren't feeding it signal at the time.

You can check the power transformer is working by checking voltages (either in the amp or at the tube sockets). To avoid damaging the OPT by running it with no speaker, remove tubes before turning it on to check voltages.

The OPT can't really be checked without connecting a speaker, whatever that takes (temporary wires or finding the required connector).

Don't worry about the diodes, power supply diodes all serve the same purpose. 1N4007 or UF4007 are commonly used these days. You're correct that a voltage reading of 35v is too low. That part number may have been used by Bogner for inventory or ordering spares/replacements, instead of describing the actual diode's characteristics.

The power supply is a voltage doubler type, meaning the power transformer puts out less voltage than you'd expect. I'd keep it, or rebuild it as shown on the schematic. If it needs to be replaced, another transformer could serve the same purpose with a more traditional circuit.

[dr.earlfunkton]

I was thinking about just alligator clipping in a speaker cable to the leads from the output jacks and plugging in the other end into a cabinet w/ the same impedance.
I notice on the schematic it says that 420V is going to the Screens of the two 6L6s. The voltage chart also states that fact. So if I hook up the speaker load and power it on, testing pin 4 (the screen) should read about 420V right? Is voltage drop expected or should it be exactly on? If I test the components in the power section and they all seem to be within good tolerance and shape, but the voltage is way off from the spec, does that mean the transformer is likely shot?
As for the rectifier diodes, does what you said mean that as long as the voltage handling is big enough, none of the other data values matter?
Thanks for the help!

[PRR]

Welcome.

Do NOT mess with the Bogen power supply or power amp (V2b onward). It is perfect. Yes, the rectifiers are probably good.

If it has been hit by lightning, 1N4007 is fine all around.

Increase the 22K in the NFB loop to 47K or 100K, *to taste*.

The tonestack is fine but may not be your style.

The too-high-gain mike preamps should be totally changed to guitar-amp style.

[dr.earlfunkton]

Welcome.

Do NOT mess with the Bogen power supply or power amp (V2b onward). It is perfect. Yes, the rectifiers are probably good.

If it has been hit by lightning, 1N4007 is fine all around.

Increase the 22K in the NFB loop to 47K or 100K, *to taste*.

The tonestack is fine but may not be your style.

The too-high-gain mike preamps should be totally changed to guitar-amp style.

The only change I might make past V2B is move the master volume post-phase inverter.

I was planning on removing the Aux and MAG entirely and changing the two Mic inputs to 1/4" obviously. One input would be "bright" and one "normal".
Instead of making each input only go through their own half of the 6EU7 before going to V2, I would send both inputs to the first half of the 6EU7, then to the tone stack, to the second half of the 6EU7, then to the 12AX7 for a third gain stage before going to the 6C4 and so on.

From some of the demos ive seen of peoples conversions of these Bogens into guitar amps, they sounded pretty farty and broke up way too easily. So I hope to achieve a better sound by changing the cathode cap values as well as messing w/ the NFB.