Sound differences xox vs. 303

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phono
 
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Re: Sound differences xox vs. 303

Post by phono »

isak wrote:hi guys

after i read what phono said i decided to replace q11 to 945.
i bought today the 945 transistor :)

my question is if i change any other of the 536 would it make any difference to the sound ?

thanks

Isak :)
Q11 is the only one to really worry about here, also you might want to try a few different betas, i found with my tests that the lower betas at Q11 sounded better. Check my thread for examples

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isak
 
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Re: Sound differences xox vs. 303

Post by isak »

Ok phono, i will thanks :)

3phase
 
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Re: Sound differences xox vs. 303

Post by 3phase »

i found that the 945 has a fatter sound to it..just replaced all 1536 in a 808 with 945...and now it has the sound i knew from my old machine...


they also behave different in envelopes..what probably explaines the significance in position q11 phono mentioned...

But i would say that having all 1536 replaced with 945 ´s will result in an overall rounder sound

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phono
 
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Re: Sound differences xox vs. 303

Post by phono »

3phase wrote:i found that the 945 has a fatter sound to it..just replaced all 1536 in a 808 with 945...and now it has the sound i knew from my old machine...


they also behave different in envelopes..what probably explaines the significance in position q11 phono mentioned...

But i would say that having all 1536 replaced with 945 ´s will result in an overall rounder sound
my 808 has all 945s in it, the 303 at the studio has 536's in it, i checked when i fixed the tacts. I've noticed that many of the vintage rolands i work on have 945's, Its my theory that towards the end of the 303 run roland probably ran out of 536's and used 945's since they had them in abundance.

pacemaker
 
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Re: Sound differences xox vs. 303

Post by pacemaker »

Hi 3phase,
i was reading this post and i immediatly searched for styroflex caps to swap C25 and C27,
but where did you find such large value ?
0.1uF is way more than the usual styroflex range no ??

bcbox
 
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Re: Sound differences xox vs. 303

Post by bcbox »

I'm starting work on x0xb0x's again after a break and I took some time to do some tests on a TB-303 of the stock 303 power supply versus the x0xb0x power supply. Here's what I did.

1. calibrated a TB-303 power supply, 5.338V/11.904V
2. recorded a pattern with both saw and square with two different settings; 4 clips total
3. removed IC16 from the TB-303 and hooked up a power supply from a x0xb0x
4. calibrated the x0xb0x power supply (hooked up to the TB-303) for 5.338V/11.904V
5. recorded the same pattern with the same exact settings as above but with the x0xb0x power supply hooked up.

The results are four clips. Each clip contains the same pattern twice. The first time it's the stock power supply and the second time it's the x0xb0x power supply. It helps to listen to the mono files through one speaker instead of two to really listen closely.
clip 1
clip 2
clip 3
clip 4


I also did some tests of the TB-303 with stock caps versus x0xb0x spec'd caps but I haven't done enough to share those results yet, I'll revisit that sometime later.

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isak
 
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Re: Sound differences xox vs. 303

Post by isak »

hi guys

i went to the electric store and asked for the styroflex caps and the guy from the store gave me this:
Image
he said that this is he's best caps.
i want to replcae c25 and c27.

do u know this caps?
what do u say guy's is it reliable?
there value is 0.1uF.

thanks from advance
Isak.

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indigenous
 
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Re: Sound differences xox vs. 303

Post by indigenous »

Hi Guys,

I have read through this thread with great interest. I used to own a 303 and sold it in 2002 when they were available on the second hand market in abundance, sadly they have all vanished and have become as rare as rocking horse poo. I really wanted a devil fish and have considered the FR-777 also, but I decied after much you tubing that the x0xb0x with the full x0xIO mod was the way to go. So rather than build my own i purchased a x0xsource x0xbox second hand here in the uk for £450.

I am quite disapointed to say the least. Yes, at certain knob settings it sounds like a 303, but it lacks that midrange 303 magic, that many of you have mentioned and discovered through carefull testing and comparison.

So I have a few questions about the x0xbox:

1. The cutoff seems to go lower and not as high as my old 303 is this correct or a build problem with my x0x?

2. The envelope amount seems to behave differently than my old 303, it seems much more dramtic as if the the exteremes emphisiased are wider than the original 303, is this xox known problem or specfic to my x0x?

3. This x0x seems to sound much more flabby when distorted than my old 303 did... Has anyone got some really good knob twiddling sound examples with the Q/C changes described in this thread?

4. The MIDI sync seems to be really poor, it looses time or just doesn't seem that tight, would i be better of just using CV gate, via the x0xIO mod or maybe Sync24 is better?


According to the x0xsource website/ebay they claim to use many of the rare components that are reported as bringing the x0x closer to that 303 sound, but this x0x sounds similar but not as good as a devil fish(well obvisously) or an original 303, it lacks that mid/high end liquid magic... In fact i am sure i have heard better sounding x0xboxs, I am really wondering if I bought a lemon :-( i will post some examples on my server and link to them for everyones opinion... If you don't mind listening to yet another 303... ;-^)

Luap
 
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Re: Sound differences xox vs. 303

Post by Luap »

Hi indigenous. I assume you are aware that one TB303 might not always sound like another TB303? Largely due to component ageing and also the fact that not all TB303's used exactly the same sets of components inside.
So similarly, one x0xb0x may not sound quite like another x0xb0x. It can even work the other way.. One might say a particular x0xb0x sounds more like the TB303 they were expecting than a genuine TB303! It is possible..
The power brick used is also known to make a difference.
The problem is, if you did not built it yourself, then you can not be certain exactly what is inside. You could open it up and take a look, but then you'd have to be reasonably good with electronics to recognise what is right and what is not. And if you could do that, then you likely could have been able to build one yourself anyway. So you are in some strange circle right there..
Still, some audio samples would be good :)

As for midi sync.. This could depend on the installed firmware. I've used both the latest stock firmware, and also the latest Sokkos firmware, and didn't notice any serious problems with either. I've a sneaky feeling stock firmware may have been more solid with regards to timing, but without time consuming testing, I could not say for sure. And if there is a difference, I suspect it is slight.. But thats just 2 firmware builds I have used. Others may be different.

Im not sure about the filter problem. The resonance can be tuned though (via an internal trim pot) it may be that this is not right and affecting what you expected of the filter?

Good luck :)

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indigenous
 
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Re: Sound differences xox vs. 303

Post by indigenous »

Hi Luap,

Yes, i know that no 2 pieces of analogue kit are the same, even the C's and R's have percentage tolerances which all add up.

One interesting point that was made in this thread was about the PCB layout of the 303. For a long time I have wondered if the transistor radio style layout contributes to the sound. In Valve amps, the valves have a certain amount of cross talk and in big guitar amps with lots of speakers this is much more apparent. Now, I know there are no components in a 303 that suffer/benefit from the micro-phony effect, but electromagnetic interaction between components spaced so tightly will have some small effect - it all adds up.

I was considering buying a devilfish from ebay, but the bidders have pushed it to a stupid price, they could have at least waited until the last 10 seconds and probably bought it for for less..lol

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... NA:US:1123

But ultimately, I think Brian, 3phase, Gaetano and phono have nailed the most important factors.

I can find the Transistors no problem and might bastardise an old Juno 6(sob) for bits, unless anyone has some pulled green transparent Xicons for sale?

I will probably look at socketing my Q's and C's to see if I can fine tune the VCO and Filter, with the PSU mod and full x0xIO mod from brian this should bring me closer to the devilfish sound i am looking for.


K

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e:pp:ik
 
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Re: Sound differences xox vs. 303

Post by e:pp:ik »

Hey indigenous

I don't think you got a lemon. More than likely it just needs a few tweaks to get it to match.

Perhaps the person that built that one didn't quite follow certain steps to match that particular sound. It wouldn't be fair or helpful to speculate. What I can say is that having gone through the process of building one I enjoyed the idea that making an 'emulation' was actually impossible if I followed the steps correctly and had the right parts sourced. It's clearly possible to make a true clone. I posted this A/B comparison a few weeks back. See what you think. I think the magic is there. I used my 303 as a reference and I didn't have to make major sweeping changes to the x0x to get it to be pretty much the same.

- A few corrected transistors
- One resistor changed

http://www.youtube.com/watch?v=_3MTZwh15b8

I'm going to swap this one for a BA6110 to do another test. I'm sure it won't be much different, other than 3-6 DB in amplitude.

Luap
 
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Re: Sound differences xox vs. 303

Post by Luap »

indigenous
If its any use, you could also shoot "alex_dubinsky" a PM. He is x0xsource.

A well set up x0xb0x is easily as good as a genuine TB303, so there should be no need at all to pay the the silly amounts of money that genuine TB303's go for these days.

Good luck 8)

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indigenous
 
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Re: Sound differences xox vs. 303

Post by indigenous »

I will do, looking at the x0xsource website, they look really well built, with careful thought and planning into what parts to use....

K

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