Hi
another LCR!!!
I am planning to write four article on Audioreview in Italy around the LCR phono
Two are done.
In attach some infos.
First of all I have built four different protos with different topology of LCR phono in the beginning with original Tango stuff and done hundreds of test , the results are collected.
Then I swicthed on Sowter 1280 ( similar to EQ-2L) just because it is in catalog and not in jewellery.
In photo 1 there is a pcb that I developped as a kit (in next future will be available); it is only the LCR stage.
In the center there is a 1280 then in the other side the components, selected.
In figura 6 there is a freq. answer of the Tango EQ-2L with the components of the board; the Zsource and Zload are the nominal described on Tango foil, 600 ohm.
The answer is fine, just a little down at 20 Hz.
The third diagram is the freq. answer of the LCR with Soter 1280.
There are some curves, the one with Zsource 600 ohm is quite smilar to the Tango and this is fine.
The other are changing the Zsource to 200 ohm, 100 ohm and 20 ohm.
The shape is equals but the level is different; this will take in consideration.
The Zload was 600 ohm
The fourth diagram is the LCR stage with Zsource 600 ohm but the Zload at 600 ( at the bottom) ohm then 100k, 47 k and 10 k
The level, of course, are high for the other Z but the response is little bit lower at 20 Hz than previous test; the shape is not very good.
With a particular software developped by Montanucci inside the Audioreview lab we can test at the best each passive components, coils included ( already shown with old threads on trafos)
In figura 1 there is a result of the test of the inductor of 1.8 H; the shape of argument and modulus are fine until the resonance at 12 kHz then the phase switch to negative ( capacitive load) and the argument decreas, very quick , this is a very good results.
In figura 2 there is the test for 0,45 mH; this is fine but the value is not high.
This to show that the quality of Sowter is high; I have already the test on original Tango but will be presented on third part where I will show a complete board with tube and LCR stage.
These test lab are real and not simulation; I can't found any complete test set on LCR stuff both for simple network and complete project.
If somenone know or has some test I will happy to share
Walter
another LCR!!!
I am planning to write four article on Audioreview in Italy around the LCR phono
Two are done.
In attach some infos.
First of all I have built four different protos with different topology of LCR phono in the beginning with original Tango stuff and done hundreds of test , the results are collected.
Then I swicthed on Sowter 1280 ( similar to EQ-2L) just because it is in catalog and not in jewellery.
In photo 1 there is a pcb that I developped as a kit (in next future will be available); it is only the LCR stage.
In the center there is a 1280 then in the other side the components, selected.
In figura 6 there is a freq. answer of the Tango EQ-2L with the components of the board; the Zsource and Zload are the nominal described on Tango foil, 600 ohm.
The answer is fine, just a little down at 20 Hz.
The third diagram is the freq. answer of the LCR with Soter 1280.
There are some curves, the one with Zsource 600 ohm is quite smilar to the Tango and this is fine.
The other are changing the Zsource to 200 ohm, 100 ohm and 20 ohm.
The shape is equals but the level is different; this will take in consideration.
The Zload was 600 ohm
The fourth diagram is the LCR stage with Zsource 600 ohm but the Zload at 600 ( at the bottom) ohm then 100k, 47 k and 10 k
The level, of course, are high for the other Z but the response is little bit lower at 20 Hz than previous test; the shape is not very good.
With a particular software developped by Montanucci inside the Audioreview lab we can test at the best each passive components, coils included ( already shown with old threads on trafos)
In figura 1 there is a result of the test of the inductor of 1.8 H; the shape of argument and modulus are fine until the resonance at 12 kHz then the phase switch to negative ( capacitive load) and the argument decreas, very quick , this is a very good results.
In figura 2 there is the test for 0,45 mH; this is fine but the value is not high.
This to show that the quality of Sowter is high; I have already the test on original Tango but will be presented on third part where I will show a complete board with tube and LCR stage.
These test lab are real and not simulation; I can't found any complete test set on LCR stuff both for simple network and complete project.
If somenone know or has some test I will happy to share
Walter
Attachments
In attach the diagram of LCR stage, only. Salme as Tango EQ-2L and EQ600P
The parallel is to get the right value following the Tango indications.
In addition the selection with LCR meter of the two value of cap.
Walter
The parallel is to get the right value following the Tango indications.
In addition the selection with LCR meter of the two value of cap.
Walter
Attachments
Some photo of the earlier protos with Tango original stuff
The first was alla Tango:
step up 999
interstage NP206 ( or 11107)
EQ-2L
intestage NP 206 (11107)
tube EC8010 and EC8020
In attach the frquency answer ( balanced out)
Then
A my Junior pcb circuit with EQ-2L and the frequency response
And the frequency response of proto of Shishido circuit always with Tango EQ-2L and TFK E88CC ( and CCA, same results)
The results are fine in alla cases.
The sound is , of course, different for each typology but always fine
Walter
The first was alla Tango:
step up 999
interstage NP206 ( or 11107)
EQ-2L
intestage NP 206 (11107)
tube EC8010 and EC8020
In attach the frquency answer ( balanced out)
Then
A my Junior pcb circuit with EQ-2L and the frequency response
And the frequency response of proto of Shishido circuit always with Tango EQ-2L and TFK E88CC ( and CCA, same results)
The results are fine in alla cases.
The sound is , of course, different for each typology but always fine
Walter
Attachments
In addition to post 1 where I show the test on Sowter inductors, here the same test on original Tango EQ-2L
The resuslts is little bit better than Sowter; for 1,8 H the peak of resonance show a very high Q, very narrow at around 14 kHz.
For 0,45 mH the results is smiliar to Sowter.
Also the deviation on nominal value is close in the Tango than Sowter.
The resuslts is little bit better than Sowter; for 1,8 H the peak of resonance show a very high Q, very narrow at around 14 kHz.
For 0,45 mH the results is smiliar to Sowter.
Also the deviation on nominal value is close in the Tango than Sowter.
Attachments
Last edited:
Some test lab published on Audioreview magazine
The freq. response
The linearity is better than the Tango specs, +/- 0, 2dB
The FFT
Only the II harmonc, the value is around 0,15 % at 1 Vout, no other harmonics and there is a flat noise carpet, normally with pho the denphasis help but in thi case th elevel is very low.
The THD vs Freq
It is costant, at 20kHz raise to 0,35 %
The ratio s/n , weighted is around -76/-78 dB
The selection of tube is always raccomended
Walter
The freq. response
The linearity is better than the Tango specs, +/- 0, 2dB
The FFT
Only the II harmonc, the value is around 0,15 % at 1 Vout, no other harmonics and there is a flat noise carpet, normally with pho the denphasis help but in thi case th elevel is very low.
The THD vs Freq
It is costant, at 20kHz raise to 0,35 %
The ratio s/n , weighted is around -76/-78 dB
The selection of tube is always raccomended
Walter
Attachments
Hi Walter,
sourcing of those tube types in good quality at affordable prices nowadays has become rather impossible. Modern reproductions are only the fourth choice anyway.
Therefore I´d rather go with russian equivalents (e.g. 6H23П aka 6N23P for 6DJ8 / ECC88).
This means direct coupling is not possible, even keep Zsource at 600ohm,
It's reported accurate with S&B and Silk LCR, so they must have some very special tuning other than getting rid of the resistors in the DC path.
In my opinion the problem of coupling is not dramatic.
If the test lab show a correct response on the most of the parameter and the listening tests are fine the goal is done.
I use the 6922/PCCC88 and works fine, with 6H30 the Cf has a lower Zout and works aklso fine.
The overload is enough for the 100% of the cases.
I will work soon with full trafo LCR with Sowter interstage trafos.
Walter
If the test lab show a correct response on the most of the parameter and the listening tests are fine the goal is done.
I use the 6922/PCCC88 and works fine, with 6H30 the Cf has a lower Zout and works aklso fine.
The overload is enough for the 100% of the cases.
I will work soon with full trafo LCR with Sowter interstage trafos.
Walter
