0

The square wave and how Q8-10 + Q28 affects it
Moderators: altitude, adafruit_support_bill, adafruit, phono, hamburgers

Please be positive and constructive with your questions and comments.

The square wave and how Q8-10 + Q28 affects it

by Sokkan on Fri Aug 08, 2008 1:35 pm

So,

I have a freshly built self sourced x0xb0x here with the only modification being a power switch. Q8-10 and Q28 are all in sockets. I made some recordings of it with a sequence running up the octaves plus one just with an accented C. The different configurations I tested are:

High beta( ~340) Q8-10 and low beta(~260) Q8-10 in combination with Q28 being 2SK30A-O, -Y and -GR and a J201. That is 8 different combinations(high and low beta with every type of Q28). The results are quite revealing when listening to just the pumping C.

I could make this a blind listening test for you, or just reveal what file is what from the beginning. You may choose. Could someone please make the files available for download, I currently have no space to put it myself, each file will be 22 seconds to thats a total of 3 minutes thus approximately 30MB uncompressed. Or any pointers to where I could put it?

Oh, please suggest more patterns to try out!
Sokkan
 
Posts: 240
Joined: Sat Sep 01, 2007 12:56 pm
Location: Stockholm

by phono on Fri Aug 08, 2008 2:20 pm

i can host them, are you on aim at all?
Image
x0x #733 Image SH-101 MC-202 TB-303 TR-606 TR-808 TR-909 MKS-50 Juno-106 A-100 Virus-B E-6400 SX-150 Monotron
User avatar
phono
 
Posts: 1502
Joined: Wed May 02, 2007 4:01 pm
Location: forum whore aka 2Cv

by Sokkan on Fri Aug 08, 2008 3:02 pm

phono: you have 2 PMs. I put it on megaupload at the moment, but it is much nicer if you could be kind to host it. It's a 18MB zip-file containing 8 wavs with names matching the content.
Sokkan
 
Posts: 240
Joined: Sat Sep 01, 2007 12:56 pm
Location: Stockholm

by phono on Fri Aug 08, 2008 3:37 pm

http://privat.bahnhof.se/wb447909/phono ... 0xTest.zip

files uploaded, i hear a difference actually, to me it sounds like the pulse width is different, its more noticable with the GR, but theres a difference between them all, albeit subtle at times. The beta doesnt seem to make a lot of difference, i suppose its since you dont have a lot of res dialed up in these clips.
Image
x0x #733 Image SH-101 MC-202 TB-303 TR-606 TR-808 TR-909 MKS-50 Juno-106 A-100 Virus-B E-6400 SX-150 Monotron
User avatar
phono
 
Posts: 1502
Joined: Wed May 02, 2007 4:01 pm
Location: forum whore aka 2Cv

by Sokkan on Fri Aug 08, 2008 3:44 pm

Yes, the differences are more than subtle if you ask me. You should put them all in your favorite DAW and switch between them. Oh, and you should loop the first and second parts separately.

My first reflection is that the -Y and -GR are very similar and the -O and J201 are quite similar, this is quite clear in the repeated C part. My second reflection is that I do not hear any difference switching between high and low betas... :shock:
Sokkan
 
Posts: 240
Joined: Sat Sep 01, 2007 12:56 pm
Location: Stockholm

by phono on Fri Aug 08, 2008 3:47 pm

Sokkan wrote:Yes, the differences are more than subtle if you ask me. You should put them all in your favorite DAW and switch between them. Oh, and you should loop the first and second parts separately.

My first reflection is that the -Y and -GR are very similar and the -O and J201 are quite similar, this is quite clear in the repeated C part. My second reflection is that I do not hear any difference switching between high and low betas... :shock:


try turning the reso up and swapping the high lows, i should take some recordings from my pwm mod v2 cos that sounds like all these at various levels
Image
x0x #733 Image SH-101 MC-202 TB-303 TR-606 TR-808 TR-909 MKS-50 Juno-106 A-100 Virus-B E-6400 SX-150 Monotron
User avatar
phono
 
Posts: 1502
Joined: Wed May 02, 2007 4:01 pm
Location: forum whore aka 2Cv

by Sokkan on Sat Aug 09, 2008 5:12 am

OK, I just send phono a new set of files. This time it is max resonance, min cutoff and a simple pattern with some accents to get the proper "boww" effect.

My conclusion from the new test is that high/low beta will make a difference, you want any of the combination of "high beta + -O", "high beta + J201" or "any beta + J201" if you ask me. Using a -Y or -GR just doesn't sound right.
Sokkan
 
Posts: 240
Joined: Sat Sep 01, 2007 12:56 pm
Location: Stockholm

by phono on Sat Aug 09, 2008 5:38 am

Sokkan wrote: Using a -Y or -GR just doesn't sound right.


ive always said this, thanks for vindicating me :D

new test files are here

http://www.bahnhof.se/wb447909/phono/x0 ... xTest2.zip
Image
x0x #733 Image SH-101 MC-202 TB-303 TR-606 TR-808 TR-909 MKS-50 Juno-106 A-100 Virus-B E-6400 SX-150 Monotron
User avatar
phono
 
Posts: 1502
Joined: Wed May 02, 2007 4:01 pm
Location: forum whore aka 2Cv

by Sokkan on Sat Aug 09, 2008 4:47 pm

Any comments? How about guest? This is a contradiction to what is currently commonly believed. Someone please protest... :wink:

One perhaps possible source of error is the beta measurement I performed. I used that built into one of my multimeters. The absolute values may be wrong, but they should still be correct relative to each other. I may build a test rigg for this if anyone is in doubt.

If anyone has a favorite pattern and settings that instantly reveals a bad square wave please give it to me and I will produce a set of sound files with it with all of the combinations.
Sokkan
 
Posts: 240
Joined: Sat Sep 01, 2007 12:56 pm
Location: Stockholm

Re: The square wave and how Q8-10 + Q28 affects it

by GoldDope on Sat Aug 09, 2008 5:10 pm

Sokkan wrote:Could someone please make the files available for download,

im amazed that after i emailed you,offering you completely free hosting,plus free FTP and actualy under the domain of x0xb0x.co.uk you still have the need to ask people here for storage space.
i give up. :wink:
Last edited by GoldDope on Sat Aug 09, 2008 6:00 pm, edited 1 time in total.
GoldDope
 
Posts: 240
Joined: Wed Dec 05, 2007 2:46 pm

by Sokkan on Sat Aug 09, 2008 5:32 pm

GoldDope: PM
Sokkan
 
Posts: 240
Joined: Sat Sep 01, 2007 12:56 pm
Location: Stockholm

by GoldDope on Sat Aug 09, 2008 5:59 pm

Sokkan wrote:GoldDope: PM

thanks mate,sorting this 4 u now ;)
GoldDope
 
Posts: 240
Joined: Wed Dec 05, 2007 2:46 pm

by guest on Sat Aug 09, 2008 11:02 pm

my ears aint the greatest
but i couldnt hear much difference
i felt the most difference was between the high and low betas

the best way to analyze it would be with no resonance
and the cutoff full up
that way as much of the frequency spectrum gets through

im glad you tested a j201
ive always been curious how much difference that made
my first clone used a j201 and it sounded awful
but there were a million other mistakes
so its hard to say where the problems came from
guest
 
Posts: 3155
Joined: Fri Feb 17, 2006 5:35 am

by Sokkan on Sun Aug 10, 2008 5:08 am

guest wrote:the best way to analyze it would be with no resonance
and the cutoff full up
that way as much of the frequency spectrum gets through


Yes, that is indeed the purpose of the first set of tests I performed, have a listen, they are here:

http://privat.bahnhof.se/wb447909/phono/x0x/Sokkan/x0xb0xTest.zip

No resonance, max cutoff, no env mod or decay.


The second tests I did was with full resonance because phono asked for them:

http://www.bahnhof.se/wb447909/phono/x0x/Sokkan/x0xb0xTest2.zip

Tonight I am going to splice together some files in which I switch randomly between different configurations, then it will be obvious I hope. :)
Sokkan
 
Posts: 240
Joined: Sat Sep 01, 2007 12:56 pm
Location: Stockholm

Re: The square wave and how Q8-10 + Q28 affects it

by buddax on Wed Mar 04, 2009 3:06 pm

The J201 actually have a nice hollow-ish sound to it, imo =)
User avatar
buddax
 
Posts: 92
Joined: Sun Dec 14, 2008 2:50 pm
Location: Denmark

Please be positive and constructive with your questions and comments.