i got the same lecture when I was starting out, with the additional caveat: "just be able to tell me what you learned from that mess and we'll call it education"
🙂
🙂
I found this bit on breadboarding:
https://forum.digikey.com/t/definitive-guide-to-breadboarding-circuits/36584
Good basic stuff plus links to further tips and techniques. Good God - start with the DIP8 OPA627s you already have and sleep well at night.
https://forum.digikey.com/t/definitive-guide-to-breadboarding-circuits/36584
Good basic stuff plus links to further tips and techniques. Good God - start with the DIP8 OPA627s you already have and sleep well at night.
Not really. Build I built a lot of audio stuff, both for my personal use and for sale.
I have been a professional audio recordist for film & video all my life, so I had a wide experience as a user. Now I'm retired.
In the late '90s I designed and built a portable professional mic preamp for video, using the SSM2017, a short adventure for the US market, and sold them all.
Redesigned a new audio project for video preamp in 2015, using THAT mic balanced chips, and presented it in the Las Vegas annual video show, but it didn't go into production. Just the prototypes.
MM preamps built only discrete ones. Projects by Graham Nalty and Elektor.
Living where I live it became difficult for me to build stuff from the beginning, that is design the pcb and fabricate it all, particularly legit parts. With Brazilian import taxes, importing parts from the USA became very expensive, shipping also did.
So I decided to go a different way. Start from existing Chinese kits and replace the passive parts. That's how I found this thread, and got help from Marcel in modifying the schematic for adding a HP filter.
This week I got the precise Aliexpress pcb that I will use to build the single chip preamp you built.
I will now open a new thread, where I will suggest how to use three different Aliexpress pcbs: a single opamp active preamp, a two opamps with passive filter preamp and a two opamps passive active preamp, as was shown here in this thread.
Gathering all the parts, including regulated supplies choices, has taken a lot of time.
Attachments
Well, I for one was just going on what I saw here - and five years ago, asking the same questions, having things string-out but I am spoiled rotten re my addiction to point-click-and ship, PayPal, 3-day delivery to my door... 0.1% Rs? Sure, how many? That new thread would be interesting.
Comments unasked for re the MOFI approach:
Comments unasked for re the MOFI approach:
Maybe I'll shut up.
I did. My recommendation is - stick with the OPA627.
I'm re-doing the RCA in and out jacks on my Marvel preamp metal enclosure. They were too cheap and are very loose-fitting with most or all of the male ICs and adapters I have. I have others now that seem a good bit better. As I've written before what I do is to not use the jack's isolation rings and allow contact between all shields and the metal case. The outboard +/- 15V linear PS is isolated from Earth and its 0V point is bonded to the case and the PCB Gnd, The TT phono leads are isolated as well so the only Earthing is through the IC shields from the 3-prong-grounded main preamp's Line input jacks which are chassis-grounded.
Are there any hard and fast rules on Earthing and/or signal grounding methods in the the case of an external MM phono cart preamp box? I have not ever had audible problems with the above method but was just wondering how the Big Boys do it.
Are there any hard and fast rules on Earthing and/or signal grounding methods in the the case of an external MM phono cart preamp box? I have not ever had audible problems with the above method but was just wondering how the Big Boys do it.