lcr phono stages

[vinylnvalves]

I have been offered some sowter LCR modules. Had a quick look on the web and haven't come up with much except the manufacturers data.
Has anyone experience of these deemphasis filters? Even new these are a lot cheaper than silk or other modern versions of the tango/pultec ones, this tends to suggest they aren't that good.

[Paul Barker]

Look good value from Sowter


1.8H /37 Ohms and 45 mH/4.2 Ohms in a single can. Developed for an RCL constant impedance RIAA circuit.. Requires external R and C components needs to be driven from a low impedance and terminated with 600 Ohms. Similar to Tango EQ-600P LCR unit. Supplied with threaded grommet mounting as illustrated.
Total Price: £87.76

I'd say for that money well worth trying.

Interesting the specific instructions above from Sowter for their version which way round to load the 600 ohm. On the exit. Would need adjusting on test, i.e. with an inverted RIAA circuit, tune the 600 ohm resistor (that being the grid resistor to next stage) to correct the inverted RIAA.

[IslandPink]

Should be good , Sowter are reliable . Will take a look later. Are they Nickel cores ?

[Paul Barker]

Are they Nickel cores ?

Most likely.

[vinylnvalves]

Like buses all info comes at once, a member of another forum by chance sent me the info to another supplier of LCR modules
http://www.roehrentechnik.de/daten/LCR- ... R-RIAA.GIF

Price isn't that much more than the full price Sowters. Interesting european supplier of wound components, probably not in the same league of AE or Tribute.
My thoughts are i would want to do is replace the RC network in a 2 stage D3a preamp, simply without to much carve up.

[Paul Barker]

http://www.roehrentechnik.de/daten/LCR- ... R-RIAA.GIF

Their unit is different from most, in that they have put the 600 ohm resistance inside the unit. Watch out for this.

My thoughts are i would want to do is replace the RC network in a 2 stage D3a preamp, simply without to much carve up.

As long as the output impedance of stage one is much lower than 600 ohms and not direct coupled, as the current drawn by the 600 ohm shunt resistor inside the unit would kill all inductance. As for that matter same for your external 600 ohm load had there not been an internal one.. like with the Sowter.

[Nick]

Their unit is different from most, in that they have put the 600 ohm resistance inside the unit. Watch out for this.

But looking at the spec, you can ignore it if you leave pin 3 alone.

[Paul Barker]

Their unit is different from most, in that they have put the 600 ohm resistance inside the unit. Watch out for this.

But looking at the spec, you can ignore it if you leave pin 3 alone.

Oh I see, 3 links it. Missed that.