Author Topic: Amp 182BA experimentation  (Read 8053 times)

AlexanderMartin

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Re: Amp 182BA experimentation
« Reply #30 on: February 19, 2016, 12:25:05 PM »
I forgot to mention that there is a resistor going from the grid/input to ground that is needed, I chose a 470k.
Since I'm making a post, here's some pictures to help some people out if they want to do this mod.
The first attachment is the high pass for the horn tweeter, second is the low pass for the woofer.

medium_grade

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Re: Amp 182BA experimentation
« Reply #31 on: April 30, 2016, 11:02:05 PM »
I forgot to mention that there is a resistor going from the grid/input to ground that is needed, I chose a 470k.
Since I'm making a post, here's some pictures to help some people out if they want to do this mod.
The first attachment is the high pass for the horn tweeter, second is the low pass for the woofer.

So, to do your mod we would have to remove the "coils in line with the woofers" and insert this new crossover circuit? Forgive me, where are these coils? The guy who restores my stuff said he could easily build the circuit above, but I don't know exactly what to tell him about the coils.

AlexanderMartin

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Re: Amp 182BA experimentation
« Reply #32 on: May 01, 2016, 09:43:49 PM »
Yes, allow me to explain further.
In the first post, I showed a picture of the "front end" of the amplifier, AKA the input circuitry.
In order to do the mod, you will want to remove the 465 ohm coil, AKA L1, C4, R4, C4, R5, and R6.
Then you will want to put in the new front end that I showed above.

medium_grade

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Re: Amp 182BA experimentation
« Reply #33 on: May 02, 2016, 09:13:49 PM »
Forgive me, is this referring to the amp(s) in the Concert Grand? I believe it's a 82-01-00.

magpie

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Re: Amp 182BA experimentation
« Reply #34 on: May 03, 2016, 09:31:32 AM »
No, AMP 182BA was found in the tube Imperial (I believe the later one).

medium_grade

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Re: Amp 182BA experimentation
« Reply #35 on: May 03, 2016, 10:17:39 AM »
No, AMP 182BA was found in the tube Imperial (I believe the later one).

Ahhhh, so these instructions will not work for my CG?

AMP82-01-00

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Re: Amp 182BA experimentation
« Reply #36 on: May 03, 2016, 01:54:13 PM »
To be honest the concert grand if all caps are restored sound good as is. However the horns cut out about 14k hz so if your wanting more high frenquency trebel add a small dome tweeter


https://www.parts-express.com/tymphany-bc25sc06-04-1-textile-dome-tweeter--264-1028

These are cheap but sound very good. I've used these to do custom builds for a few very picky guys.

Just a thought


David        "If it ain't interesting, its really just boring"

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Re: Amp 182BA experimentation
« Reply #37 on: May 13, 2016, 08:37:16 PM »
To be honest the concert grand if all caps are restored sound good as is. However the horns cut out about 14k hz so if your wanting more high frenquency trebel add a small dome tweeter


https://www.parts-express.com/tymphany-bc25sc06-04-1-textile-dome-tweeter--264-1028

These are cheap but sound very good. I've used these to do custom builds for a few very picky guys.

Just a thought

Perhaps. I'm not so much disappointed with the highness of amp. I do enjoy the way symbols and acoustic guitars sound on this thing. It's more of the attack frequencies which tend to be a bit harsh.

So, will this mod not work with my amp at all?

voxACthirtee

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Re: Amp 182BA experimentation
« Reply #38 on: May 13, 2016, 11:03:59 PM »
I'd guess the point would be the same.
If you have CG, then the power in those amps is able to give you both the level of highs and lows you need.
If you are not happy then i would look elsewhere for solutions.


You just popped into this thread without giving much info.
You have CG? Has it been gone through? Completely?
Recapped? Re-tubed? You should go through that checklist before you even contemplate any sort of mod.
I would also do a simple check to see that all the speaker wires and connections are in good shape, or even just put some higher grade stuff in there all around. Can't hurt.

They are also 55+ year old drivers. Those horns probably have, what,  Phenolic diaphragms? Maybe you can have them redone as well.
Old magnets, depending on how hard they were ridden and how much mechanical vibration they endured will also demagnetize some in 50+ years.

Can't say exactly what you are hearing or why, but check those things off before you mod a CG amp

AlexanderMartin

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Re: Amp 182BA experimentation
« Reply #39 on: May 14, 2016, 02:29:12 AM »
Ok guys, I have a confession, I messed up. I got it BACKWARDS.
On the schematic above, it says .0022 for the bass caps, and .022 for the treble caps.
They are actually .022 for the bass caps, and.0022 for the treble caps.
I am INCREDIBLY sorry for anyone who installed this mod and had it not work, I deserve every bit of grilling that I may receiver in the future. I haven't been able to login as my computer gave me a fritz and I had to reinstall a battery connector and whatnot, so I have not had any opportunity to update this. You can all commence on grilling me, as I rightfully deserve every bit of it.  :'(

As for the CG questions, I honestly don't think you need this mod, I do think it will help the horns perform a bit better but considering those have 3 pairs of 6V6's on them for the bass, you BETTER be getting good response!

Consoleman

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Re: Amp 182BA experimentation
« Reply #40 on: June 05, 2016, 09:36:32 AM »
So I installed this (corrected) crossover in my AMP-150 which is driving twin horns and twin woofers in the '56 mono Berkshire. I haven't been able to reach Alexander for a few weeks now so thought I'd post impressions.

As for the low-pass, the bass signal is extremely attenuated going through the 10k resistor, to the point where the volume has to be turned almost all the way up to get any sound out of the woofers. As for the treble, it's very bright when using a modern source, a little too bright as cymbals tend to dominate the sound on a recording like Take Five. It doesn't sound so bright using the CR-730 tuner since that source has a softer sound. Overall the horns have a "modern" sound that I'm not used to hearing from a 50s console.

I'm no crossover expert but I think this is worth pursuing and experimenting further. If I could figure out the problem with the bass and soften the treble a bit it could sound really nice. Any suggestions would be appreciated.
Mark

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Re: Amp 182BA experimentation
« Reply #41 on: June 09, 2016, 10:15:33 AM »
Replaced almost all 12AX7 tubes with Telefunkens. MUCH better. More depth, clearer/smoother highs, more detail, excellent. Didn't really help the bass, but the unit does sound less harsh to me. Big improvement.