907 / 914 output level comparison ...

System 55 • System 35 • Model 15
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Rarecomponentadsr
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Joined: Mon Aug 24, 2015 5:08 pm

907 / 914 output level comparison ...

Post by Rarecomponentadsr » Sat Jan 16, 2016 3:50 pm

I'm slightly concerned my 907 DIY clone may be slightly underpowered but wonder is this normal behaviour.?

The output level is very roughly half of that compared to a straight saw wave output direct from a 901b.
I notice on schematics the buffers on the 914 have been increased and wonder if this was a result of the 907 being underpowered ? The other alternative is a wiring or other fault in my clone.

EMwhite
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Re: 907 / 914 output level comparison ...

Post by EMwhite » Mon Jan 18, 2016 1:56 am

Rarecomponentadsr wrote:I'm slightly concerned my 907 DIY clone may be slightly underpowered but wonder is this normal behaviour.?

The output level is very roughly half of that compared to a straight saw wave output direct from a 901b.
I notice on schematics the buffers on the 914 have been increased and wonder if this was a result of the 907 being underpowered ? The other alternative is a wiring or other fault in my clone.


That's a bit of a head scratcher, for sure. I've read, as well, that the output is somewhat reduced but I have a 907a in my Model 15 and I never noticed this; perhaps I'm not giving it a good enough side-by-side A/B.

I also don't have anything the way of scientific spectrum analysis equipment. I had a Dave Jones Otool module in the Euro portion of my modular but had to sell it in a mad scramble to afford a Liberation that came available locally.

Maybe I'll have a look around for some DAW software that will produce measurement of various frequency bands and see what I can find out.

Is the signal loss even across the range? More pronounced at lower frequencies? Interested to see what you've experienced and how you measured it.
'76 Minimoog, Taurus 3, Oberheim FVS + Son of 2-voice; Sequential ProOne; Juno 106; Moog Model 15; Kurzweil 250; Hammond M3; and a handful of Fender Basses Flickr!

Rarecomponentadsr
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Re: 907 / 914 output level comparison ...

Post by Rarecomponentadsr » Tue Jan 19, 2016 8:13 am

Thanks for your reply to this query. The signal out seems to be weak on all frequencies right across the range although all the frequencies are working correctly .
I have a YouSynth 914 and this module does emit are far stronger signal than my 907 clone but again I wondered if this was normal behaviour with the 914 having extra buffers and I know that Yves created quite a faithful replica here.

I suppose the best action will be to remove my 907 and check thoroughly for any wiring faults etc.

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noddyspuncture
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Re: 907 / 914 output level comparison ...

Post by noddyspuncture » Tue Jan 19, 2016 10:16 pm

I have an R.A.Moog 907 to which I fitted a bypass switch so I can leave it patched in all the time.

There is no "boost" as such - all controls fully clockwise should be: "what goes in comes out" level-wise...? The controls only cut on the designated frequency band.

Mine seems to behave in this manner, although I do notice a slight tonal difference between active and bypassed when using the in/out switch with all controls set to maximum.

Cheers,
Tom

Rarecomponentadsr
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Re: 907 / 914 output level comparison ...

Post by Rarecomponentadsr » Wed Jan 20, 2016 8:20 am

Thanks.

If it's a case of "what goes in comes out" then I will certainly check the wiring and my input and output buffers.
If I take a saw signal from a 901b into a CP3 and then take a Pulse wave from the same oscillator and direct it thru the 907 and then back into the same CP3, then the first saw wave totally dominates without question. Not just by a little but quite significantly .....so indeed I'm pretty sure I must have a fault in the 907 clones
Input/output section.

EMwhite
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Location: Middlesex

Re: 907 / 914 output level comparison ...

Post by EMwhite » Wed Jan 20, 2016 9:52 pm

I haven't gotten back to mine but what Noddy said is about what I remember. Granted, mine is a brandy new 907a which is based on inductors from Cinemag but henry is henry.

Again, if somebody can recommend a windows or preferably mac based level monitoring tool or daw plug-in, that would be grand.
'76 Minimoog, Taurus 3, Oberheim FVS + Son of 2-voice; Sequential ProOne; Juno 106; Moog Model 15; Kurzweil 250; Hammond M3; and a handful of Fender Basses Flickr!

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