Yorkshire Hi-Fi Club
#346 Re: Yorkshire Hi-Fi Club
Some info. Ali left the Modwright phono with me. Measurements are interesting. The RIAA has a rising response above 2k, will post some graphs later, one channel shows a rising response below 500Hz as well, but the other shows a falling response. I will investigate further. Distortion also shows much higher on one channel (0.12% against 0.06% at 1v output 1kHz), so the two things may be related and might be a valve issue, I will do some swapping later today and see what I find.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#347 Re: Yorkshire Hi-Fi Club
Being one who was very impressed with the performance of the the ModWright presented by Ali.
Are the measurements being reported a falling away from the as new models measurements ? .
Would it be possible to report back if any works carried out, have a audible effect on the sound quality that can be heard, if corrections that are deemed required are put into place ?.
Are the measurements being reported a falling away from the as new models measurements ? .
Would it be possible to report back if any works carried out, have a audible effect on the sound quality that can be heard, if corrections that are deemed required are put into place ?.
#348 Re: Yorkshire Hi-Fi Club
Well, I have no idea what the as new model measurements would be as I don’t have such a unit on hand. I have not removed the case yet, my plan was the swap the valves between channels and see if the higher distortion and rolled off bass followed the valves.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#349 Re: Yorkshire Hi-Fi Club
I also measured the input impedance of the preamp used last week, and its as previously said, 3k (I wanted to check it wasn’t a typo on the web site as all their other preamps have a higher value for the single ended inputs). So a good spot there, and it will certainly affect the valve stages performance.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#350 Re: Yorkshire Hi-Fi Club
Modwright frequency response. input set as MM, 1mv input. Same with MC.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#351 Re: Yorkshire Hi-Fi Club
Ok, the droopy response follows the 6n1p, so probably worth getting a couple more and picking the best pair. Nicely built as I remember from repairing Modwright kit in the past. The MC input is handled by three 2sk170's for each chan it seems. I also remember now that they like battery bias so the output stage has a 3.6v lithium cell for each channel. I think that may explain the sonic signature of the unit. Battery bias was always a bit of a Marmite thing.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#352 Re: Yorkshire Hi-Fi Club
The valves were all new NOS Nick, will get some more.
Thanks for taking the time, it’s appreciated. Any thoughts on mods?
Thanks for taking the time, it’s appreciated. Any thoughts on mods?
#353 Re: Yorkshire Hi-Fi Club
I would leave well alone. Its very possible that the distortion I heard at David’s was down to the 3k load from the preamp. I don’t hear it here. Could try and get the RIAA flatter, but I would get the two channels to match first.
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- The Stratmangler
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#355 Re: Yorkshire Hi-Fi Club
No.
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#356 Re: Yorkshire Hi-Fi Club
Then its 47kΩ https://soulution-audio.com/series5/sou ... amplifier/
Chris
#357 Re: Yorkshire Hi-Fi Club
#358 Re: Yorkshire Hi-Fi Club
I stand corrected, its the 520 so it has got the phono stage.The Stratmangler wrote: ↑Sat Jun 02, 2018 8:27 pmThe Soulution preamp used has the built in phono stage?
But not sure what bit of "I measured" you were unsure about?
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
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#359 Re: Yorkshire Hi-Fi Club
Nothing whatsoever.
There's nothing to question about "I measured".
I thought I'd ask, just because of the oddity in the specification in that particular preamp.
3kΩ input impedance is what I'd expect to see on a microphone preamp, not a linestage preamp - the loading is likely to tilt the EQ of line level equipment plugged into it.
Chris
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#360 Re: Yorkshire Hi-Fi Club
Its this baby
https://soulution-audio.com/series5/sou ... amplifier/
Never thought to try the built in phono stage!! Bummer.
https://soulution-audio.com/series5/sou ... amplifier/
Never thought to try the built in phono stage!! Bummer.
You can't change how people treat you or what they say about you. All you can do is change how you react to it.
Mohandas Karamchand Gandhi
Mohandas Karamchand Gandhi