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Graham Slee View Drop Down
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Points: 16298 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jan 2021 at 4:58pm
Originally posted by patientot patientot wrote:

Graham, I'm no engineer, but I think this must explain the problem. Looks like a 20 ohm output was used which recorded the gain at 59.2dB instead of 62dB. I actually thought they might have been testing an older version of the Reflex C because the gain didn't match current specs. Looks like it was just tested wrong.

Here's my layman's arithmetic. 

59.2db = a gain factor of 912

The correct gain factor should be 1260

912 divided by 1260 = 72.38%


Oh, and by the way, I didn't know that was one of his measurements/complaints before I wrote


I never visited his website and I don't recall you telling me about this.
That none should be able to buy or sell without a smartphone and the knowledge in how to use apps
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Graham Slee View Drop Down
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Points: 16298 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jan 2021 at 5:05pm
@ David, I'm interested in his suggestion that the Reflex C has a rumble filter, according to John C. As I refuse to be wound-up by ASR, I won't go along myself to look. Like most people my age I have to consider my blood pressure.

John C mentioned something about the FFT which allegedly illustrates a peak in the response due to the "rumble filter". Can you explain this for me?

PS: you may not be an engineer but you're good at the maths!
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Points: 1525 		Post Options Post Options   Thanks (0) Thanks(0)   Quote patientot Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jan 2021 at 5:14pm
Originally posted by Graham Slee Graham Slee wrote:

Originally posted by patientot patientot wrote:

Graham, I'm no engineer, but I think this must explain the problem. Looks like a 20 ohm output was used which recorded the gain at 59.2dB instead of 62dB. I actually thought they might have been testing an older version of the Reflex C because the gain didn't match current specs. Looks like it was just tested wrong.

Here's my layman's arithmetic. 

59.2db = a gain factor of 912

The correct gain factor should be 1260

912 divided by 1260 = 72.38%


Oh, and by the way, I didn't know that was one of his measurements/complaints before I wrote


I never visited his website and I don't recall you telling me about this.

Right, this confused me at first but now that you have explained the output from the analyzer was wrong I understand, or at least well enough for a layman. 
SL-1200 MK7 (modified) + Reflex M + PSU-1 used with AT150-40ML, AT VM95ML, Stanton 680mkII + Ogura, and Shure M35X cartridges.
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Points: 1525 		Post Options Post Options   Thanks (0) Thanks(0)   Quote patientot Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jan 2021 at 5:18pm
Originally posted by Graham Slee Graham Slee wrote:

@ David, I'm interested in his suggestion that the Reflex C has a rumble filter, according to John C. As I refuse to be wound-up by ASR, I won't go along myself to look. Like most people my age I have to consider my blood pressure.

John C mentioned something about the FFT which allegedly illustrates a peak in the response due to the "rumble filter". Can you explain this for me?

PS: you may not be an engineer but you're good at the maths!

His frequency response test (inverse RIAA test tones?) shows a "hump" of 0.5dB from around 30Hz to 50Hz, which gradually tapers off before showing a very accurate RIAA curve response. Amir calls that a "bass boost" and concludes it is due to a high pass rumble filter. 

Having read your previous posts on not liking rumble filters this obviously has me confused. 

Re: Amir's complaints, it seems his main complaints were the overload margin, which he assumes is too small and will exaggerate clicks and pops, and the mains noise and general distortion. I will conclude that the latter is due to the wrong input on his analyzer as you explained above. 




Edited by patientot - 13 Jan 2021 at 5:20pm
SL-1200 MK7 (modified) + Reflex M + PSU-1 used with AT150-40ML, AT VM95ML, Stanton 680mkII + Ogura, and Shure M35X cartridges.
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CageyH View Drop Down
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Points: 1678 		Post Options Post Options   Thanks (0) Thanks(0)   Quote CageyH Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jan 2021 at 5:49pm
it also proves the point that he has never listened to one.
Kevin
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patientot View Drop Down
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Originally posted by CageyH CageyH wrote:

it also proves the point that he has never listened to one.

He doesn't like vinyl AFAIK and does not even own a turntable AFAIK. His forte is mainly digital audio, again, AFAIK. 
SL-1200 MK7 (modified) + Reflex M + PSU-1 used with AT150-40ML, AT VM95ML, Stanton 680mkII + Ogura, and Shure M35X cartridges.
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Points: 1678 		Post Options Post Options   Thanks (0) Thanks(0)   Quote CageyH Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jan 2021 at 5:58pm
So it is likely to be a completely unbiased review then?
Kevin
European loan coordinator, based near Toulouse, France.
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