A new-production BBD, with added features!

[gtfields13]

I received a few of these from CabinTech this week. I decided to use this as my first excuse to also try adding JLPCB's PCBA service, so I put together a small (17x27mm) PCB with the circuit and components from the SSI 2100's typical application circuit. I set this up to connect out to a parent circuit through a pin header.

I don't pay more than the lowest shipping option, so I expect it will take a few weeks for these to show up.

 

[giovanni]

I received a few of these from CabinTech this week. I decided to use this as my first excuse to also try adding JLPCB's PCBA service, so I put together a small (17x27mm) PCB with the circuit and components from the SSI 2100's typical application circuit. I set this up to connect out to a parent circuit through a pin header.

I don't pay more than the lowest shipping option, so I expect it will take a few weeks for these to show up.

View attachment 109421

Awesome. Looking forward to hearing your thoughts on the chip!

 

[gtfields13]

A set of these prototypes arrived yesterday while I was driving across the country. I think this is more of a "teaser" post. I am not going to have time to touch these for a while - the rest of life has decided to raise a crisis that takes priority...

 

[gtfields13]

A set of these prototypes arrived yesterday while I was driving across the country. I think this is more of a "teaser" post. I am not going to have time to touch these for a while - the rest of life has decided to raise a crisis that takes priority...

Well - quick assessment is the SMD board is not functional. Pfft. I have signal and clock going into the SSI2100, but am not seeing anything come out.

I have a couple of leads to check - one possibility is my clock is not suitable (SA555P setup for 86kHz and 48% duty cycle). I think this should be working but am going to try out a CD4047 as clock alternative.

Alternatively, and a bigger issue, is the VTbias capacitor SMD I used may not be suitable for the SSI2100. In this case, the board design is the problem and would need to be reworked. I would also probably add a location for a gain capacitor on the board when I revise.

If the alternative clock doesn't work, I will probably have to mount up an SSI2100 onto a carrier board and breadboard out the whole circuit...

 

[Cybercow]

Well - quick assessment is the SMD board is not functional. Pfft. I have signal and clock going into the SSI2100, but am not seeing anything come out.

I have a couple of leads to check - one possibility is my clock is not suitable (SA555P setup for 86kHz and 48% duty cycle). I think this should be working but am going to try out a CD4047 as clock alternative.

Alternatively, and a bigger issue, is the VTbias capacitor SMD I used may not be suitable for the SSI2100. In this case, the board design is the problem and would need to be reworked. I would also probably add a location for a gain capacitor on the board when I revise.

If the alternative clock doesn't work, I will probably have to mount up an SSI2100 onto a carrier board and breadboard out the whole circuit...

Any update on this?

 

[gtfields13]

Any update on this?

No. I have been busy mostly with my professional work, and with things that are working a bit better. I did take a second look, and the second time I was measuring, I didn't see my input signal coming through to the output of the buffer OpAmp, but didn't have time to debug the new problem!

If you send me your address, I will drop one of these in the mail to you and you can have a look at it. I would welcome your thoughts or observations, since I would like to get the BBD working - I have a specific use case for a basic mono-to-stereo analog adapter to use delay to add space

My working theories are:

1. I didn't properly respect the data sheets recommendation on using an electrolyic for VTBias capacitor, and perhaps this needs to be taken off-board (for the current PCB with a proper electrolytic instead of the SMD capacitor I used here.
2. Using an SA555 as the timer is not adequate. I think these are better than a basic 555, but possibly the rise isn't fast enough or the signal isn't close enough to 50% duty, although I measured it quite close. I was going to stick a flip-flop in front of my timer to improve, whcih would only cut my timer down to around 43kHz, which is still wtihin reasonable performance for the BBD.

Gregory

 

[Scruffie]

No. I have been busy mostly with my professional work, and with things that are working a bit better. I did take a second look, and the second time I was measuring, I didn't see my input signal coming through to the output of the buffer OpAmp, but didn't have time to debug the new problem!

If you send me your address, I will drop one of these in the mail to you and you can have a look at it. I would welcome your thoughts or observations, since I would like to get the BBD working - I have a specific use case for a basic mono-to-stereo analog adapter to use delay to add space

My working theories are:

1. I didn't properly respect the data sheets recommendation on using an electrolyic for VTBias capacitor, and perhaps this needs to be taken off-board (for the current PCB with a proper electrolytic instead of the SMD capacitor I used here.
2. Using an SA555 as the timer is not adequate. I think these are better than a basic 555, but possibly the rise isn't fast enough or the signal isn't close enough to 50% duty, although I measured it quite close. I was going to stick a flip-flop in front of my timer to improve, whcih would only cut my timer down to around 43kHz, which is still wtihin reasonable performance for the BBD.

Gregory

For what it's worth, I saw someone on Modwiggler tried to play with this chip and found the chip wouldn't function with a less than optimal duty... which makes one sort of wonder why they didn't just put a flip-flop instead of an inverter inside the chip.

Also, don't know if it's of any use but have you looked at the vintage EHX Ambitron regarding mono-to-stereo?