Analog to Digital Converter Suggestions?

Daikini · 18518

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Offline Daikini

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Reply #15 on: May 31, 2014, 03:26:01 PM
After some ripping and listening, I decided that the Linestreamer wasn't making the best of the signal coming from my Seduction- the bass was pretty thin. In hindsight, this should not have been a surprise, as the linestreamer has a 5K input impedance.

So I thought about getting some sort of buffer to match things up. But then it occurred to me that I already have resistors on hand, why not change the input impedance?

This is the kind of dumb thinking that often gets me into trouble. I had to remove the existing surface mount resistors and solder in the replacements across the tabs of the circuit board mounted RCA jacks. I had never played with surface mount stuff before, so visions of ruining an expensive board were dancing in my head. I managed to get it done without destroying anything, but it was a little scary.

The result is quite pleasing. With 51K input resistors in the linestreamer, the bass is much better, and the recording level is higher, but doesn't go into clipping. I think I was lucky, this could have gone wrong so many ways.

So I suppose the moral of the story is that the Linestreamer is not a good out-of-the-box match for the Seduction, but it can sound good if you can do something to get the impedance into a range the Seduction can deal with.
 

David Gray

Empire 208/Jelco 750d/Nagaoka mp300 -> Seduction -> Stereomour ->Klipsch Heresy IIs w/ dual Polk PSW10s
Sony CDP-CX235 -> Schiit OptiModi -> Sex 2.1 -> Madisound BK-12m/Hifiman HE400


Offline Paul Birkeland

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Reply #16 on: May 31, 2014, 04:42:42 PM
The real question is why the input impedance was set so low to begin with...

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Daikini

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Reply #17 on: May 31, 2014, 04:59:52 PM
Yeah, it's odd. I'm totally ignorant when it comes to digital gear, but could there be some reason internal to the A-to-D converter for setting it low?

David Gray

Empire 208/Jelco 750d/Nagaoka mp300 -> Seduction -> Stereomour ->Klipsch Heresy IIs w/ dual Polk PSW10s
Sony CDP-CX235 -> Schiit OptiModi -> Sex 2.1 -> Madisound BK-12m/Hifiman HE400


Offline John Swenson

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Reply #18 on: June 04, 2014, 08:49:13 AM
Most ADC chips have lower distortion when driven by a low impedance. Most AD boxes will put a buffer in front of the ADC chip in order to do this. I don't know if the one you have does that or not, you should be able to tell if there is an op-amp in the path from input to ADC chip.

If it is not buffered they might have put the low value resistor there to sort of give the ADC chip a low impedance to ground.

John S.

John Swenson
DAC designer
Well Tempered Record player -> Seduction
Moded Squeezebox->DIY DAC
BDT preamp->813 monster SE amp
DIY "Bazooka" Lowther speakers


Offline Daikini

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Reply #19 on: June 04, 2014, 02:36:39 PM
It does have an op-amp first thing in the signal path.

David Gray

Empire 208/Jelco 750d/Nagaoka mp300 -> Seduction -> Stereomour ->Klipsch Heresy IIs w/ dual Polk PSW10s
Sony CDP-CX235 -> Schiit OptiModi -> Sex 2.1 -> Madisound BK-12m/Hifiman HE400


Offline Aural Robert

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Reply #20 on: June 07, 2014, 06:11:25 AM
I am using an M-audio sound card which has RCA inputs and running my tt through a small preamp and into my pc. The seduction output level was too low to register on my recording software (Spin It Again). I've digitized ~500 lps so far.

We can compare files as an interesting experiment. I'll send you say Led Zeppelin I've recorded, and you send me your recording of the same song / album, and we can compare the relative sound qualities. Of course there a lot of other variables like tt, cartridge, bit rate etc. But it would be fun to try.

Let me know. Anyone else out there want to compare?

Aural Robert.
... I've got Mercury poisoning ...

Origin Live Calypso TT w String Theory arm & Shure V15VxMR, Eros or BH DAC -> BeePre -> MonAmor 2A3s w JJ's => Blumestein Bamboo Tritons on Blumenstein Bamboo stands, AND Enhanced SEX w Sexy spkrs and subs in the WAF zone. DIY Belden 89259 w Eichmann interconnects throughout


Offline Daikini

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Reply #21 on: June 07, 2014, 08:42:08 AM
That sounds fun. I think the hard part will be finding records we have in common. My collection is mostly what I could find at thrift stores and garage sales, so it's pretty random.

Here are a few that I have that lots of folks might have:

The Cars, self titled
Jackson Brown, Running on Empty
Bruce Springsteen, Born in the USA
Dire Straits, Brothers in Arms

If none of those are matches, name a few of yours, maybe I'll have them.

David Gray

Empire 208/Jelco 750d/Nagaoka mp300 -> Seduction -> Stereomour ->Klipsch Heresy IIs w/ dual Polk PSW10s
Sony CDP-CX235 -> Schiit OptiModi -> Sex 2.1 -> Madisound BK-12m/Hifiman HE400


Offline Grainger49

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Reply #22 on: June 08, 2014, 06:16:05 AM
If you have mostly Thrift Store finds, surely you have both of Peter Frampton's hits and some Herb Alpert.

There are just albums that you always find at Thrift Stores.  I should start a thread in Music.



Offline Daikini

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Reply #23 on: June 08, 2014, 08:42:44 AM
I avoid Herb Alpert, for no apparent reason. But I do enjoy the Baja Marimba Band. Go figure!

David Gray

Empire 208/Jelco 750d/Nagaoka mp300 -> Seduction -> Stereomour ->Klipsch Heresy IIs w/ dual Polk PSW10s
Sony CDP-CX235 -> Schiit OptiModi -> Sex 2.1 -> Madisound BK-12m/Hifiman HE400


Offline Grainger49

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Reply #24 on: June 08, 2014, 11:21:35 AM
I have a Baja Marimba Band collection from when they were new.  Notice, just about every cover has a guy, with his back to the photographer, relieving himself.

Check it out!



Offline denti alligator

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Reply #25 on: March 21, 2015, 03:05:56 PM
I'm looking for a decent ADC for vinyl rips. Is the E-MU 0404 out of production? What's a good ADC in that price range that also does 24/192?

- Sam

Rega P3-24 (w/AT 150MLX) w/Groovetracer upgrades / Eros II / FLAC >J.River >DSD256 >Gustard X20 / Moreplay > Stereomour II / Klipsch Forte II w/Crites upgrades / C4S S.E.X. 2.0 +Nickel MQ Iron / Speedball Crack / Sennheiser HD600 w/Cardas cable


Offline denti alligator

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Reply #26 on: April 03, 2015, 04:05:06 AM
Maybe pick up an EMU 0404USB? I have used one to digitize tape recordings to 192/24 and it seems to do a decent job. You just need RCA to 1/4" phone plug adapters.

Doc, just to confirm: I would send the L/R RCA from my phono pre to the EMU? I'm looking at pictures of it and don't see where I would input these (1/4" or otherwise).

- Sam

Rega P3-24 (w/AT 150MLX) w/Groovetracer upgrades / Eros II / FLAC >J.River >DSD256 >Gustard X20 / Moreplay > Stereomour II / Klipsch Forte II w/Crites upgrades / C4S S.E.X. 2.0 +Nickel MQ Iron / Speedball Crack / Sennheiser HD600 w/Cardas cable


Online Doc B.

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Reply #27 on: April 03, 2015, 05:08:16 AM
Use RCA to 1/4" phone plug adapters on your phono preamp output cables. They go in the Mic/Hi-Z/Line inputs. Those are combination XLR/1/4" phone jacks.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline denti alligator

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Reply #28 on: April 03, 2015, 11:20:53 AM
Use RCA to 1/4" phone plug adapters on your phono preamp output cables. They go in the Mic/Hi-Z/Line inputs. Those are combination XLR/1/4" phone jacks.

Thanks, Doc, that makes sense now!

- Sam

Rega P3-24 (w/AT 150MLX) w/Groovetracer upgrades / Eros II / FLAC >J.River >DSD256 >Gustard X20 / Moreplay > Stereomour II / Klipsch Forte II w/Crites upgrades / C4S S.E.X. 2.0 +Nickel MQ Iron / Speedball Crack / Sennheiser HD600 w/Cardas cable