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Re: Phono Transfer System Construction Information

Posted: Mon Jul 13, 2020 7:56 am
by JR.
mediatechnology wrote: Sat Jul 11, 2020 7:50 pm Last November I got a puppy - a Spaniel/Border Collie mix.
Very high energy dog...
It's been hard for me to build boards to replace what I've sold.
One day last week there were 4 young puppies loose wandering around my neighborhood. They were gone within 24 hours so either their owner collected them again, or they found new homes. They looked cute from a distance, but I didn't let them learn my scent. :lol:

About 6 months ago a young dog, not a puppy but not a mature dog, apparently broke his rope and was running loose. It wasn't a huge dog, looked like a setter but apparently strong as evidenced by the broken rope. I grabbed the frayed end of the rope and held on for dear life. That young dog pulled me around like a rag doll. Before that incident I almost considered getting another dog but that convinced me to let that idea go.

JR

Re: Phono Transfer System Construction Information

Posted: Tue Dec 22, 2020 2:40 pm
by mediatechnology
I got asked to make a "minimalist" RIAA EQ/Monitor board that is switchable between flat and RIAA EQ on the Record output.

Image

Re: Phono Transfer System Construction Information

Posted: Fri Jan 22, 2021 6:48 pm
by crin
somehow, this board looks familiar… :lol: reminds me of east texas: sparsely populated :mrgreen:

Re: Phono Transfer System Construction Information

Posted: Sun Feb 28, 2021 6:02 pm
by billshurv
I've been quiet as been a mad few months with work (hammering square pegs into round holes in software) and home schooling has left me little time for anything else. But the square pegs are now hammered firmly in and he goes back to school in a week. What I have managed to do is get one MM board and monitor switcher complete and hooked up as loose boards. Having not used an MM cartridge since 1987 I've got no references for goodness, but seems to work and the audio technica cartridge I've hooked up performs nicely. A lot of people complain it's bright. I suspect they are way too high on capacitance. Currently mine is just loaded with the cables from the TT which seems to work, at least until I can get the next thing fixed to let me measure FR.

A tiny bit of mains buzz but given lose board lash up and no real attention to grounding yet I'm not going to fret until I box things up (and it may be due to the miniDSP). Next step get my microtrack II working. Let's see if I can get that done in less than 2 months!

Re: Phono Transfer System Construction Information

Posted: Sun Feb 28, 2021 7:03 pm
by mediatechnology
I figured you had lots of things going on.
We hadn't heard from you in awhile.

Glad you got it built and are able to give it a listen!

Re: Phono Transfer System Construction Information

Posted: Mon Mar 01, 2021 5:29 am
by billshurv
I have to say I am enjoying the fact that this breaks nearly every rule that audiophools hold dear and still works superbly.

I've also become convinced a lot of the vinyl lovers don't want to get close to the master tape and instead hunt for an alternative reality. Which is sort of OK given how flawed the vinyl medium is, but I get my kicks trying to be as neutral as rock dragging allows.

Sadly some furniture changes over lockdown have made the acoustics worse in the living room, so I will have to recomission the headphones..

Re: Phono Transfer System Construction Information

Posted: Mon Mar 01, 2021 6:40 am
by mediatechnology
billshurv wrote: Mon Mar 01, 2021 5:29 am I have to say I am enjoying the fact that this breaks nearly every rule that audiophools hold dear and still works superbly.
Thanks Bill!
I will wear that as a badge of honor.

Re: Phono Transfer System Construction Information

Posted: Mon Mar 01, 2021 6:59 am
by crin
billshurv wrote: Mon Mar 01, 2021 5:29 am I have to say I am enjoying the fact that this breaks nearly every rule that audiophools hold dear and still works superbly.
do you consider douglas self one of these audiophools, too? :D after all, he is staunchly opposed to balanced phono preamps. they are noisier than a single ended circuit – and needlessly so, he writes, since balanced circuitry offers no advantages but a lot of penalties … :roll: :roll: :roll: (sez me who by now uses four of wayne's unneccessarily balanced MM-, 1 just as needlessly balanced MC-preamp plus two EQ/switcher boards. at least the RIAA is not balanced or else i couldn't spin an LP whilst reading his book on small signal audio design. 8-) )

Re: Phono Transfer System Construction Information

Posted: Mon Mar 01, 2021 7:07 am
by billshurv
No I consider Doug as someone who is impossible to debate with once he has made up his mind. There is of course a way to get a noise reduction with balanced if you go to a current rather than voltage design, but driving a virtual gound with MM brings a whole new set of interesting problems. And yes I have one of those on the bench for eventual testing.

Re: Phono Transfer System Construction Information

Posted: Mon Mar 01, 2021 12:58 pm
by JR.
billshurv wrote: Sun Feb 28, 2021 6:02 pm I've been quiet as been a mad few months with work (hammering square pegs into round holes in software) and home schooling has left me little time for anything else. But the square pegs are now hammered firmly in and he goes back to school in a week. What I have managed to do is get one MM board and monitor switcher complete and hooked up as loose boards. Having not used an MM cartridge since 1987 I've got no references for goodness, but seems to work and the audio technica cartridge I've hooked up performs nicely. A lot of people complain it's bright. I suspect they are way too high on capacitance. Currently mine is just loaded with the cables from the TT which seems to work, at least until I can get the next thing fixed to let me measure FR.

A tiny bit of mains buzz but given lose board lash up and no real attention to grounding yet I'm not going to fret until I box things up (and it may be due to the miniDSP). Next step get my microtrack II working. Let's see if I can get that done in less than 2 months!
hi Bill...

MM carts are sensitive to termination capacitance. High and low capacitance cables, and length, should be considered when going for a target termination.

I used to sell a kit 4 station dip switch and PCB with 24pF, 47pf, 100pF and 200pf polystyrene caps to cover a wide range of terminations.

There used to be frequency response test records, but I don't know how many playings it takes to compromise their HF accuracy. I don't think I'd look for one of them in the used vinyl bin.

In my judgement termination (capacitance) was not well appreciated back in the day, and may be responsible for mixed results from similar gear.

JR