JoaMat Posted March 22, 2015 Report Posted March 22, 2015 (edited) / Edited November 11, 2015 by JoaMat
Pars Posted March 23, 2015 Report Posted March 23, 2015 Avnet still has the MPSW56. Good price too. That's where I got mine from for the multi-amp. http://avnetexpress.avnet.com/store/em/EMController/GP-BJT/ON-Semiconductor/MPSW56RLRAG-BKN/_/R-8954392/A-8954392/An-0?action=part&catalogId=500201&langId=-1&storeId=500201&listIndex=-1&page=1&rank=0
xianghao Posted March 23, 2015 Report Posted March 23, 2015 losts of 6s4a (NOS) in here: http://www.ebay.com/itm/221716637541 but Unfortunately, they has been sold yesterday....... $52 for about 35......
kevin gilmore Posted March 23, 2015 Author Report Posted March 23, 2015 actually everything i did was 3 oz copper, mainly for the filament traces. Also good for higher currents found in ssdynahi etc. and yes i own a metcal now, someone gave me one. hard to go back once you use one for a while. previously i was using a 40 year old weller.
Earspeakers Posted March 23, 2015 Report Posted March 23, 2015 losts of 6s4a (NOS) in here: http://www.ebay.com/itm/221716637541 but Unfortunately, they has been sold yesterday....... $52 for about 35...... Aladdin rebrand of 70's RCA? That's a new one. Avnet still has the MPSW56. Good price too. That's where I got mine from for the multi-amp. Thanks, I picked some up, I'm sure they'll be used somewhere in one of these amps. I'm assuming they're no different (sonically or other) from the 2SA970?
spritzer Posted March 23, 2015 Report Posted March 23, 2015 Thanks spritz. Rhetorical question: do the Mafia ever produce an amp that doesn't take an obsolete part? Well I do love your work; about to finish a KGST, a KGSSHV is partially done, a Megatron has been started, and just assembled the parts for the T2. The KGDT is completely current production.. Off the shelf too...
Earspeakers Posted March 23, 2015 Report Posted March 23, 2015 The KGDT is completely current production.. Off the shelf too... Got any boards? My goal is to build every Mafia Stax amp Here's a KGST, KGSSHV and Megatron being built simultaneously. KGST is practically done, T2 is on its way
eggil Posted March 23, 2015 Report Posted March 23, 2015 Can you elaborate on the KGDT? I missed that one.
Earspeakers Posted March 23, 2015 Report Posted March 23, 2015 (edited) Can you elaborate on the KGDT? I missed that one. A one tube simplified KGST IIRC, or something like that. I came across it here I thought, but am unable to find it again. Edit: I think this was it, but no elaboration. The layout files are up on Kevin's site, but no PDF schematic Edited March 23, 2015 by Earspeakers
valve5425 Posted March 23, 2015 Report Posted March 23, 2015 Avnet still has the MPSW56. Good price too. That's where I got mine from for the multi-amp. http://avnetexpress.avnet.com/store/em/EMController/GP-BJT/ON-Semiconductor/MPSW56RLRAG-BKN/_/R-8954392/A-8954392/An-0?action=part&catalogId=500201&langId=-1&storeId=500201&listIndex=-1&page=1&rank=0 I was looking to use the MMBTA56LT1G SOT-23 version, which can dissipate 225 ma max. Looking at the schematic it shouldn't exceed that. BUT..... I'd be much happier using the 1A TO-92. Trouble is, Avnet US want $40 to ship to UK, and if I buy from Avnet Europe, it's minimum of 2000! Now I guess I wouldn't be using all those! So, if anyone's got some spare, I'd be happy to take them off their hands for a fair price + shipping, Paypal fees, etc.
charlo89 Posted March 23, 2015 Report Posted March 23, 2015 Hi, I have 2 sets from the previous GB, I would like to know where can I buy the transformer for US volatage, and for the heatsink, do I need to connect the heatsink to the ground ? Moreover, this may sound stupid but what tin use ?, I remember when a made a B22 AMB advised some kind of tin. Do you think that KGST may fit in this case ? http://www.aliexpress.com/store/product/3607T-Silver-rounded-aluminum-amplifier-chassis-AMP-Enclosure-case-BOX/1360518_1982669752.html whith the tube outside (socket screw to the top and connected with wire on the PCB) Thank you
nopants Posted March 23, 2015 Report Posted March 23, 2015 if you have the boards you should be able to derive measurements for an appropriate case after picking one of the transformers mentioned in this thread 63/37 with a small diameter should work fine
Earspeakers Posted March 23, 2015 Report Posted March 23, 2015 (edited) Do you think that KGST may fit in this case ? http://www.aliexpress.com/store/product/3607T-Silver-rounded-aluminum-amplifier-chassis-AMP-Enclosure-case-BOX/1360518_1982669752.html whith the tube outside (socket screw to the top and connected with wire on the PCB) Still have heat sinking to deal with. That one is pretty small IMO, might work. KGDT board Edited March 23, 2015 by Earspeakers
headinclouds Posted March 23, 2015 Report Posted March 23, 2015 I was looking to use the MMBTA56LT1G SOT-23 version, which can dissipate 225 ma max. Looking at the schematic it shouldn't exceed that. BUT..... I'd be much happier using the 1A TO-92. Trouble is, Avnet US want $40 to ship to UK, and if I buy from Avnet Europe, it's minimum of 2000! Now I guess I wouldn't be using all those! So, if anyone's got some spare, I'd be happy to take them off their hands for a fair price + shipping, Paypal fees, etc. Someone posted a few pages back that RS in UK has the MPSW56, (which they do)) and also the smd device you seek. Search uk.rs-online.com
Pars Posted March 23, 2015 Report Posted March 23, 2015 ^ They show backordered... wonder if they'll get them Temporarily out of stock - back order for despatch 24/03/2015
JoaMat Posted March 23, 2015 Report Posted March 23, 2015 (edited) / Edited November 11, 2015 by JoaMat
Looser101 Posted March 24, 2015 Report Posted March 24, 2015 Local supplier is showing over 1000 pieces of MPSW56 made by Motorola. If anyone is interested drop me a PM.
insanity Posted March 24, 2015 Report Posted March 24, 2015 I thought for all the Stax amps the MPSA Series is completely fine. So no need to get MPSWs...
Kerry Posted March 24, 2015 Report Posted March 24, 2015 I've used SOT23 versions for the front end of the KGSSHV and KGST which are lower power than the mpsa series. They get a little warm but run and sound great. I don't see an issue with the mpsa series for the front end of the ES amps.
spritzer Posted March 24, 2015 Report Posted March 24, 2015 No problem using the MPSA parts. The newest boards have had their labels updated As for the KGDT, it's pretty much a KGST that you can tuberoll. It was designed around the ECC99/12BH7A and 6N6pi with selectable current levels but I'll probably scrap that idea when I finalize the boards. It is bound to cause problems... Anyway, it is a cracking little amp. Reposting this for anybody who might not have seen it: Finished... Hi, I have 2 sets from the previous GB, I would like to know where can I buy the transformer for US volatage, and for the heatsink, do I need to connect the heatsink to the ground ? The heatsinks have to be grounded, always.
valve5425 Posted March 24, 2015 Report Posted March 24, 2015 Re. the MPSW(A)56...........Thanks for your response everyone! RS UK do have 700 in stock, min purchase of 50. It's been a couple of months since I checked with them, and ironically I drove past the warehouse this afternoon,. Doh!! Mouser UK have 5000+ of the MPSA's, minimum purchase of 1, so, in view of spritzers advice, and the fact I've a fistful of parts to get from them anyway, I'll go with MPSA. A lot less pain than the SOT23's I've got. It was a PITA trying to find the pesky little things in their anti-static bag, let alone the thought of having to solder them!
nopants Posted March 25, 2015 Report Posted March 25, 2015 for the people who are using the onboard heatsinks, what temperatures are you getting? also how hot does the top plate get during operation? I realized this is the first time I built something using a "normal" enclosure
gepardcv Posted March 25, 2015 Report Posted March 25, 2015 Looking at MPSA56 parts on Mouser, and most are discontinued, just like MPSW. This is the only exception. Is that what you guys are using?
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