Stripped down transformerless 1176 workalike project

[Dyonight]

Unfortunately I'm not as smart as you guys are with electronics but I' more than interested in this kind of build! I'd like 16 channels of simplified 1176 and this thread is a godsend!

I'll stay around to see how it turn out!

 

[grrrunge]

I was thinking, if I use a compressor as an insert, in TRS on my console, it be unbalanced, so in this configuration it's useless to have a balanced input and a balanced output.
It would be another way to cut the cost ... but maybe you are not going to use them in a TRS insert.

Of course. The mixer in our studio has unbalanced insert points as well, but we're looking to upgrade it in near future, so I wanted to keep the balanced in/out just in case.
The balanced out is just two resistors and a cap. The balanced in is one half dual op-amp and a handful of components.  Moneywise there's no big savings to be made there

 

[fjgaston]

yes, you are right.
Another question, as I would be interested in comparing the transformerless version with transformer version, would it be easy to add input and/or output transformers on this board ?

(I would like to build, for example,  7 transformerless and 1 with transformer to be able to compare them)

 

[grrrunge]

It would be easy enough. Just replace R62 with the transformer primary, and take your output from the transformer secondary.
The primary impedance should be pretty high though. Otherwise the op amp might have a hard time driving the transformer.

 

[jordan s]

Any way to rekindle interest in this project?

 

[pvision]

Any way to rekindle interest in this project?

grrrunge has put a lot of hard work into it. It would be a shame for it to go to waste

Of all the projects I'd like to tackle, an 1176 is #1. I know exactly how I'd want it to sound and what features I'd want

I'd build it perhaps even more stripped down. I don't care about LED meters - I'd rather have a VU like the original

The USP of the 1176 is the way it sounds but I suspect ergonomics & the extreme simplicity of the original design play a significant part in their continuing appeal

Nick Froome

 

[grrrunge]

I'm still interested in this project as well. Real life just got in the way

 

[pvision]

How can we help with the project ?

Nick Froome

 

[grrrunge]

How can we help with the project ?

Nick Froome

I'll have to look at everything again, as it's been a solid while since i last worked on this. A thorough schematic lookover to spot any mistakes would be awesome.

If anyone has got info on obtaining 2:1 and 6:1 ratios, that would be awesome too.

I'm also thinking about replacing the FD333 diodes with BC546's configured as diodes to obtain low leakage diodes without having to source the FD333's. Any comments on this?

 

[peterc]

Hi

I'm also interested and willing to help out.

Peter

 

[MerlynMetal]

Hi,

I was looking for a guitar pedal size 1176 project like Cali76 pedal and came across this thread.
I'm almost done drawing the PCB based on the one posted here but I have couple of questions:

1/ Since BC550C are considered low noise aren't those a better choice instead of the more common type BC546/7?
2/ I'm planning of powering the unit from a standard guitar effects 9VDC wall wart which means a DC to DC onboard converter will be necessary maybe based on the LT1054 charge pump which can provide up to 100mA and then regulated.
Considering that the final amplifier/transformer is not there how much will be the total current draw of the unit?

Some changes I'm planning is to use the LM3914 led driver if that's not going to require too much current from the DC converter otherwise I don't care about it.

Also I found a schematic with 1:4/6/8/10/12/20 ratios but I don't know how accurate are those values. Maybe some of you who are more into this will advise. Since it's going to be used mostly with a bass guitar I'm wondering if those additional ratios will be  of any use at all?

Looking at the gutshots of a Cali76 unit and some other 1176mono  clones I noticed that they have a dual gang Input potentiometer. Any ideas why?

 

[arjepsen]

Did this project ever go any further?
Very interested, as I'm also trying to figure out how to cut the circuit down into guitar-pedal form, a-la cali76