New guy with many questions. Bassman sound

[strat68ntx]

Hi y'all. I've been tinkering with pedals for a while now and I'm wanting to build an amp. I'm acquiring an old SG brand 410 cabinet. My dream amp is a bassman 410. The old Heart sound, without the flanger.
My plan is 2 ROG Azabache pedals as preamps, with an on board cab sim. What power amp would I need to gig with this? I'd like to use it for my back line with the direct out to the PA. Unfortunately I don't have the wattage of the existing speakers and I'm not sure I'll be keeping them anyway.

Any ideas? Kits... Layouts... Whatever y'all can tell me would be very appreciated. Thanks.

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[J M Fahey]

Hi y'all. I've been tinkering with pedals for a while now and I'm wanting to build an amp. I'm acquiring an old SG brand 410 cabinet.

Cool.
If possible, post a picture of its guts plus some speaker close up, showing labels and stamped codes, if any; just curious as to what speakers could they have used way back then.
CTS/Jensen/Oxford/Rola/Utah/???

My dream amp is a bassman 410.

<3)

The old Heart sound, without the flanger.
My plan is 2 ROG Azabache pedals as preamps, with an on board cab sim. What power amp would I need to gig with this?

I guess you´ll need "something else"  in between, at least some basic guitar premp such as Rod Elliot´s or similar one with guitar EQ and tone controls; otherwise sound will be dull or very dull 
Those pedals expect a guitar amp, which is always treble oriented; any power amp will be flat, that´s why you need a guitar equalized preamp in between.

Also ditch the speaker emulator which is a grandiose name for a treble cut .... what you don´t need , and besides ... you will use real guitar speakers   .... so .....

I'd like to use it for my back line with the direct out to the PA. Unfortunately I don't have the wattage of the existing speakers and I'm not sure I'll be keeping them anyway.

Any ideas? Kits... Layouts... Whatever y'all can tell me would be very appreciated. Thanks.

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[strat68ntx]

https://goo.gl/photos/raTNEGMv1r8Kteyo7

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[strat68ntx]

Each one is 4 ohms

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[strat68ntx]

Here's one as it was originally.

http://c-nelson.com/1974-cmi-sg-systems-sg-410/

[strat68ntx]

Several years back a friend of mine was given a Lowery Genie organ. I'm not sure of the exact model, but it had been lit on fire for some reason. He passed the charred carcass on to me. It still worked, sort of. It made sounds. Likely not the sounds it was supposed to make, but..

In any case, I tore it down, and I have this. Can anyone tell me if this would be a decent amp for guitar?

[J M Fahey]

Thanks for the pictures  :tu:

[phatt]

Hi Strat,,
There would be many odd bits of circuitry like this that *Could Be* made into a guitar amplifier,,,
*IF* you want to do the hard work and back engineer it all. xP

Will it make a good guitar Amp? Likely Not.

Also Re your first Q,, It's highly unlikely that the circuits you mention will get you close to a Bassman sound.
Although Fet circuits do look similar to Triode circuits and do respond in a different way than transistors they don't sound the same as a real Valve circuit,,, as it's far more complicated than the copy and paste mind set of some people who build Fet circuits and claim it does the Valve thing.
Yes you can get Valvey sounds from SS gear but you have to work in a different way.

Search for posting by *KMG* who has likely designed one of the best Emulations of Valve amplification using SS devices.  Note high voltage circuits and Transformers are involved and make a big difference. 8|

Phil.

[J M Fahey]

What I see there is a transistor power amplifier and power supply, probably around 20/30W which is what would hav been suitable for such an organ.
I bet you also have the speakers, show them too.

You may use that amp as a general purpose bench amp, or, imitating *old*  tube combos, you may mount the power amp and supply in the bottom of a cabinet and a gutar preamp on top, similar to:

The general idea is "heavy stuff on bottom, light stuff on top"

One problem is that your amp does not show a power switch, nor audio input or speaker out.

Of course, all that is hidden in some of those connectors, I bet the organ had a power switch in some convenient location, audio was carried to speakers, sound came from the keyboard generators and power was sent to feed the organ section.

IF you kept the wiring harnesses, you might have an easier task; if you must solve that maze from square one, it will be difficult.

I do NOT recommend randomly shorting connector pins to each other trying to find which turns amp on, now if you already identified a cable which goes to the power switch and back, and flipping that switch turns amp on, then that´s better.

[exztinct01]

First time I see something like this. I might try this one as I'm having hard time finding enclosure for my heatsink 100mm tall.

[strat68ntx]

That looks really cool. I like keeping the weight low. Great idea.

My quest continues. I had bought an old Fender M80 Chorus about 5 years ago, it was working great even though it had a broken pot shaft on the OD channel volume. So I played it for a while with pedals, and I ordered the pot and some new knobs (it was missing a bunch).

I took it apart and changed the pot out, and had it working. I then got a great deal on an even older Peavey Deuce VT. I left the M80 sitting apart for about 3.. maybe 4 years. I had noticed that the OD channel circuitry looked pretty pedal like.

I then found this thread.http://music-electronics-forum.com/t42579/ and gleefully decided to mod my M80, since it was already apart. So I changed out the parts, and put in some sockets for the clipping diodes. (LED1 and LED2)

Well, that was a bad plan. I don't know why it never occurred to me that the layout was different between the M80 and the M80 Chorus. I wound up totally limiting the clean channel output. I did get some really interesting sounds from different diodes though. At that point, the overheating problem started up.

Looking around I found a thread that Enzo had posted, I can't remember which forum though, about that problem. So I've ordered some grease and the mica parts to hopefully fix this thing.

I also saw the resistor swap in the bias string (look at me acting like I know what I'm talking about) but.. again, the layouts are different. So I found both schematics and I found the correct parts to mod on the OD channel. (C11, R26, R27) I'll find the bias string later tonight.

In the mean time, I had ordered a regular grey carpet M80, an 89 model. (Mine is a 1990)
It works great and I'd love to hear it with those mods but I'm terrified to take it apart, lest it stop working too!

I've got the 410 wired 4ohm and the M80 is  STUPID LOUD(!!) through it.

My next ideas have been

Fender FM 65 DSP or 212 DSP as a possible amp to put in, or I found a Behringer V-Tone GMX1200H at Guitar Center for not too much.

[strat68ntx]

I do have the speaker and the wiring harness from the organ... somewhere. Maybe in the shed? I'll have to go and hunt for it next weekend when I'm home.