The Motown eq

[pucho812]

Thank you for your reply.
View attachment 96604View attachment 96605I don't have any knowledge or skills about tube, so I think it will be a transistor circuit.
I haven't picked up the circuit yet, but I'll upload a photo that isn't on the blog.
The lowest and highest frequencies.
Precise inductors and capacitors are required to make a copy.

well with the amount of make ups gain needed could do a pultec style make up amp

 

[emrr]

As I’ve said in other threads about those Cinema / Langevin 251 / Altec 9061/9062 / Hycor EQ’s, if you’re feeding 10K or higher input Z it works perfectly well to use a 600:10K step up transformer on the output as makeup gain. I’ve done it, I’ve measured it.

 

[pucho812]

As I’ve said in other threads about those Cinema/Langevin/Altec/Hycor EQ’s, if you’re feeding 10K or higher input Z it works perfectly well to use a 600:10K step up transformer on the output as makeup gain. I’ve done it, I’ve measured it.

any noise issues?

 

[emrr]

any noise issues?

Why would there be?

 

[FIX]

The old UA 175 compressors in the LINE mode was typically used to regain the signal level of these.

 

[CJ]

a lot of wire footage in that thing, but they did not care as much about noise back then as AM radio was hash city.

 

[limo]

I can't find it anywhere on the net, I drew a schematic for altec 9062a. Please download from the blog as I will not link directly here.
Since it is Japanese, please translate it automatically and read it.

『傑作altec9062a その2　回路図作成』

 

[thomasdf]

Wow ! Thanks for your work ! That's amazing

 

[alphasnk]

Thank you for sharing that Limo, it's a beautiful hommage you did to that eq

 

[Script]

Rinku taihen arigatou.

Thanks for the link.

 

[Rowboat]

I can't find it anywhere on the net, I drew a schematic for altec 9062a. Please download from the blog as I will not link directly here.
Since it is Japanese, please translate it automatically and read it.

『傑作altec9062a その2　回路図作成』

Outstanding work!

 

[limo]

Thank you for many access. but...I am sorry, found a mistake.

5KHz slot ... wrong= pin4R+560R >>> right = pin5R +560R

The blog has already been corrected.　
If you downloaded it, please download it again from the direct link below.

https://media-uploader.work/?mode=dl&id=2535&original=1&key=75381f01-c300-44b5-aafd-17621d42f952




connector has not solderd.

 

[guiguru]

awesome work, thank you so much limo.

2 gotchas that I found:

1) C2 @ 12,5kHz is 19.9nF, not 11.9. the value is visible in the bottom pic in post #20

2) all these resistors look to me to have gold tolerance bands. thats 5%.

thanks again, —ps

 

[limo]

Thanks for your support.
Some people pointed out mistakes in messages.
I also found one mistake...orz

inductors value uH >>> mH

I uploaded a new file here

https://media-uploader.work/?mode=dl&id=3775&original=1&key=084b283d-a394-4493-a888-0b8f19a50ddf

It seems to be a topic on other forums as well.
Some inductor values were written and some were missing, so I removed them all and measured them.
Some of the written values were consistent and some were not.
The numbers in the table are measured values.
Resistors and capacitors are not measured.

 

[yohan34]

252A, which may be the same as the Altec 9062a (they look pretty much identical, anyway.)