el-bee Posted November 13, 2007 Report Share Posted November 13, 2007 Yey, the Dalbani-supplied 2SA733s turned out to be crap, hfe's are between 150-215 in the batch I got. Luckily these weren't expensive..Can anyone suggest some other source _than_ Mouser? What about replacements? If high gain is the only critical value for these trannies I'm thinking these shouldn't be too difficult ones to find a replacement for.. say, BC559 has a max. gain of 800 (although 125 typical) and seems, at least at a glance, to match some of the other specs as well. The x0xb0x wiki suggests 270-310 for the p-model you can buy from Mouser. What about the k-model, anyone know where to source those? Quote Link to comment Share on other sites More sharing options...
b-funk Posted November 13, 2007 Report Share Posted November 13, 2007 i got some 2sa733p from segor.de, and quite a few of those are hfe 300-320... Quote Link to comment Share on other sites More sharing options...
Sasha Posted November 13, 2007 Author Report Share Posted November 13, 2007 If high gain is the only critical value for these trannies I'm thinking these shouldn't be too difficult ones to find a replacement forThat is what I thought too but didn`t do any exploration on that subject. So, from 100 peaces of 733`s what is best one can expect to get? Quote Link to comment Share on other sites More sharing options...
b-funk Posted November 13, 2007 Report Share Posted November 13, 2007 i bought 50 of those at segor, and maybe 15 have hfe over 300, most are between 270 and 300, and the rest is between 190 and 270, so it´s quite a good bunch i got...but i have some 2sa733ak, but didn´t check for hfe reading yet..best wishes,tobias Quote Link to comment Share on other sites More sharing options...
Sasha Posted November 13, 2007 Author Report Share Posted November 13, 2007 15 from 50... not bad! :) I wouldn`t expect more than 10. Quote Link to comment Share on other sites More sharing options...
Jaicen Posted November 13, 2007 Report Share Posted November 13, 2007 Any idea what part of the circuit the trannies are in??? It may be possible to sub them for something with higher hfe values to get it going. You could always swap them out later if they're not quite right (though I suspect a number of different NPN's could be used without much difference in the sound. Quote Link to comment Share on other sites More sharing options...
el-bee Posted November 14, 2007 Report Share Posted November 14, 2007 Any idea what part of the circuit the trannies are in??? It may be possible to sub them for something with higher hfe values to get it going. You could always swap them out later if they're not quite right (though I suspect a number of different NPN's could be used without much difference in the sound. They're PNPs and located in the VCF section, namely Q9 and Q10..i got some 2sa733p from segor.de, and quite a few of those are hfe 300-320...Damn, shipping to Finland 31 eur :( .. Would anyone be willing to sell/ship me a small batch (say max. 4) of hfe measured p or k -model 733s? Preferably somewhere within EU so I can do a direct BIC/IBAN transfer (no extra charges for the transfer). Quote Link to comment Share on other sites More sharing options...
el-bee Posted November 14, 2007 Report Share Posted November 14, 2007 Oh sorry, missed the part about the maxi letter :) Quote Link to comment Share on other sites More sharing options...
Goblinz Posted November 14, 2007 Report Share Posted November 14, 2007 I know this is thinking way ahead but I've been looking at some knobs! We could save a bit on buying a few of the same type. I really like the curved ones in the opening post with the white marker.I've been having a look at various sites and put a page up with a few different knobs on. Click here to take a lookhttp://fullmoon-festival.110mb.com/knobs/knobs.html.Personally I think that "A" and "C" would go really well together, but I do like "B" very much. What are people's thoughts on this, do we want to arrange a group buy or are people happy sorting themselves out? G Quote Link to comment Share on other sites More sharing options...
el-bee Posted November 19, 2007 Report Share Posted November 19, 2007 Hehe, funny thing. Just when I was wondering what to do with the 7SA733s, I spotted some old Marantz amp in the trash whilst taking out some of mine.. Decided to check/salvage it for parts and, what do you know, found 4 7SA733APs inside \:D/ .. Best pair out of these gives a hfe of 315, call it a problem definitely sorted out!I reckon I'll be definitely stripping every single piece of audio hardware I find in the trash for parts from now on ;). Quote Link to comment Share on other sites More sharing options...
Goblinz Posted November 19, 2007 Report Share Posted November 19, 2007 Ooooh.... nice idea. I have a really old amp somehwere at home that I was going to try and fix up... will have a look tonight. G Quote Link to comment Share on other sites More sharing options...
Sasha Posted November 19, 2007 Author Report Share Posted November 19, 2007 That`ts nice catch Arto. Keep up digging the electronic junk. There is gold in some of it! ;) Quote Link to comment Share on other sites More sharing options...
el-bee Posted November 30, 2007 Report Share Posted November 30, 2007 A little something to go along with the b0x, http://www.analoguerenaissance.com/TS303/ ;) Quote Link to comment Share on other sites More sharing options...
Sasha Posted November 30, 2007 Author Report Share Posted November 30, 2007 I think I`ve seen it already before. Sounds good, and it is pretty small. Thanks for the link. ;)EDIT:I`ve just seen the price tag:A rough estimate of the price is ± 110€.Well, it seams this thing is for reach real TB owners and not us DIY folks. I spend some time browsing his website... the guy is charging 80EUR just for changing LEDs! >:( I would not buy this FX from him now, even it is half the price. Quote Link to comment Share on other sites More sharing options...
TheAncientOne Posted November 30, 2007 Report Share Posted November 30, 2007 I agree with the DIY price tag thing, but I do think, considering that he is in Belgium, running a VAT regsitered company, then the price is not too out of line with the cost of a top flight guitar pedal, and the build quality is good, (apart from the fact that I'd want a decent shielded meal case). In medium quantities, (100 off) 4 Spectrol pots will cost me 15.78€, (that's for linear, conductive plastic, logs are about 2/3 more), so I don't think he's profiteering. Given his samples I do know one thing: he isn't going to light up any dancefloors with his 303 programming!On that front, though, I've got an 808/Muff hybrid distortion unit design around here somewhere, which I'd started adding a Vactrol based voltage controlled distortion to. I was thinking in terms of a thin board with edge mounted pots, then they could be racked up for things with more than one channel, and controlled in tandem. I'll dig the design up in the New Year and have a go, (got to put a floor in my loft before then - then I'll have some space to work). The dynamics thing he talks about is simply a side chain device. By doing a bit of crafty design, it can also act as a noise gate, because distort FX are inherently noisy due to the high gains involved, which he doesn't seem to have thought of, and would be good for recording. I've been reading a lot on compressor technology recently - I've ordered a couple of boards to try out: Mnats take on the 1176, http://www.geocities.com/m_natsume/1176.html and the 'Picocompressor' http://www.picocompressor.com/picocomp/index.htm. I want to design a side chain breakout unit that will route the compressing signal into the side chain, or all of it, as required. Some of the older gadgets like this were great - I remember reading Jon Hiseman's trick of gating the snare or Hi-Hat with and Allison 'Kepex' triggered by (say) the Bass drum to get emphasis on the beat. Of course the ultimate in dynamics messing is with a vocoder, but the though of buying all those polystyrene caps for the filters is putting me off, just as much as the build time.(Wandering again....)Mike Quote Link to comment Share on other sites More sharing options...
Sasha Posted December 25, 2007 Author Report Share Posted December 25, 2007 Still waiting for PCB company to inform me when can we expect the PCB`s but I don`t think it will be this year. I`ll keep you updated. Quote Link to comment Share on other sites More sharing options...
Sasha Posted December 26, 2007 Author Report Share Posted December 26, 2007 I just get email from PCB company. The deadline for is 20.01.2008. Not very soon, but at least we know the deadline. ;) Quote Link to comment Share on other sites More sharing options...
Kartoshka Posted December 26, 2007 Report Share Posted December 26, 2007 actually it's right on time! ;) fine enough. i hope i'll finally get my cnc done untill then too. Quote Link to comment Share on other sites More sharing options...
b-funk Posted December 26, 2007 Report Share Posted December 26, 2007 hooray!!!xoxxoxxoxxoxxoxxoxxox... Quote Link to comment Share on other sites More sharing options...
Sasha Posted December 26, 2007 Author Report Share Posted December 26, 2007 I think some porno search engine could bookmark this pages as there is to many "X" here. ;D Quote Link to comment Share on other sites More sharing options...
ganchan Posted December 26, 2007 Report Share Posted December 26, 2007 may i ask a quest?what do you would say when you say.. ??? :o 8)"Modifications:main PCB will have all buttons inline, so button caps can be rotated 90 degrees and won`t stick out of line.io PCB will have pads for connecting the wires for power switch so no trace cutting is needed." :-\ Quote Link to comment Share on other sites More sharing options...
Sasha Posted December 26, 2007 Author Report Share Posted December 26, 2007 Can you please explain your question. I really don`t understand it. ??? Quote Link to comment Share on other sites More sharing options...
ganchan Posted December 27, 2007 Report Share Posted December 27, 2007 sorry, you're right, i'm a little bit stupid in this period :)seeing the main PCB i've understand about button. you means the 4 in the right side that are not at same level of the others righ? Quote Link to comment Share on other sites More sharing options...
Sasha Posted December 27, 2007 Author Report Share Posted December 27, 2007 Exactly. I want to rotate mine 90 deg. and allow other to rotate it as they wish. Quote Link to comment Share on other sites More sharing options...
dj3nk Posted January 9, 2008 Report Share Posted January 9, 2008 i hope that the deadline is not dead :) Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.