Search found 69 matches

by nic
Mon Dec 11, 2023 12:42 pm
Forum: Buying and Selling
Topic: Items for sale : Shizuki polyprop in oil 45uF 450VAC film caps GM70 sockets
Replies: 1
Views: 5398

Items for sale : Shizuki polyprop in oil 45uF 450VAC film caps GM70 sockets

Up for offer
Chinese gold plated GM70 sockets , £12 a pair including postage

New old stock Shuzuki (now ASC) polypropylene in oil , metallised film caps . 450VAC rated so rated 630VDC . 58mm diameter , 120mm tall up to lip . spade terminals . £11 each plus postage

UK only please
by nic
Fri Oct 27, 2023 1:11 pm
Forum: Solid State
Topic: A fun little BJT buffer
Replies: 2
Views: 2242

Re: A fun little BJT buffer

Thanks , no magic smoke yet . I can see why I'm getting a bit of drift. As this started as a Diamond , I bolted the BD139/140 drivers to the heatsink and left these in place when I rejigged into a CFP output stage . I think these need to be thermally isolated from the main heatsink The BD are probab...
by nic
Thu Oct 26, 2023 8:25 pm
Forum: Solid State
Topic: A fun little BJT buffer
Replies: 2
Views: 2242

A fun little BJT buffer

Recently starting playing with BJT amps , have only ever used BJT in power supplies , CCS etc before so have been getting used to the Vbe thing . Have built a few breadboards and originally intending this experiment to be a diamond buffer but a bit optomistic with the NPN/PNP Vbe matching of the dev...
by nic
Fri Dec 09, 2022 11:48 pm
Forum: Buying and Selling
Topic: 3c24
Replies: 7
Views: 5528

Re: 3c24

100TL is a lucky find :)
by nic
Fri Dec 09, 2022 10:13 pm
Forum: Buying and Selling
Topic: 3c24
Replies: 7
Views: 5528

Re: 3c24

It's not just the filament , although the filaments are fragile with spiral filament thoriated tungsten valves like 3C24 . Running fils only at first use can help condition a valve , some valves do get hopelessly gassy and can't be recovered . You need to operate the valves with some colour in the a...
by nic
Wed Dec 07, 2022 3:49 pm
Forum: Buying and Selling
Topic: 3c24
Replies: 7
Views: 5528

Re: 3c24

I have some Heintz and Kaufman 3C24 going spare . NOS but boxes have disintegrated . You do know the caveats of using these valves ?

cheers

Nic
by nic
Wed Feb 10, 2021 12:59 am
Forum: Everyones Projects
Topic: Another MoFo
Replies: 87
Views: 35577

Re: Another MoFo

Those devices are about £5 a piece for genuine parts , stockists that hold parts for amateur radio usually hold them such as RFparts.com . With a generous enough heatsink running at 20 watts dissipation should be ok . I have tried IRF verticals , laterals (BUZ900P) , Semisouth R085's and R100's and ...
by nic
Mon Feb 08, 2021 11:04 am
Forum: Everyones Projects
Topic: Another MoFo
Replies: 87
Views: 35577

Re: Another MoFo

Fakes a plenty on Ebay . Just make sure if you intend using those devices , buy from a reputable source or you'll just get reprinted IRF510 :)
by nic
Sun Feb 07, 2021 11:48 am
Forum: Everyones Projects
Topic: Another MoFo
Replies: 87
Views: 35577

Re: Another MoFo

Those 35mH chokes work well as loads hf amp.jpg . Been running my follower amp , using four (2 in PSU , 2 as loads) , for a while . Getting nice sounds out of the thing . I left the top cover off until I can get round to playing with bias circuitry , it's running rather lean at 1A bias at present . ...
by nic
Sat Jan 02, 2021 7:43 am
Forum: Headphones
Topic: simple latfet hpa
Replies: 12
Views: 18388

Re: simple latfet hpa

Look into the Mitsubishi RD16HHF1 . It's an RF lateral TO220 device , very low capacitance so more fragile and lower dissipation than the Exicons , needs a much higher value of gate stopper (470R-1k) and requires around +5V on the gate to bias to 1A . Availability is the main caveat and Ebay is full...
by nic
Fri Jan 01, 2021 6:36 pm
Forum: Buying and Selling
Topic: kT90 Valves
Replies: 4
Views: 3968

Re: kT90 Valves

I have some KT90 somewhere that I swapped for some other valves a number of years ago . Coin-base pip-top Groovetube brand so I guess these were carefully screened . I know some of the early EI valves had issues but I think these are the good ones with the welded anodes

Any use ?

cheers

Nic
by nic
Sat Dec 26, 2020 8:02 am
Forum: Everyones Projects
Topic: Another MoFo
Replies: 87
Views: 35577

Re: Another MoFo

If you require a choke for midbass use upwards , consider the Triad C-56U . 35mH 2A . About £12 a piece at Mouser . I have an amp under construction that uses one per channel in CLC power supply and as choke load for the output stage

cheers

Nic
by nic
Fri Dec 20, 2019 5:50 pm
Forum: Buying and Selling
Topic: PTFE Teflon equipment wire
Replies: 6
Views: 6445

Re: PTFE Teflon equipment wire

I just notice the price on the 19/0.25 wire was incorrect , it should be advertised at £1.20 a metre
by nic
Tue Oct 15, 2019 10:45 am
Forum: Valves
Topic: CV4003 / ECC82 types...
Replies: 6
Views: 11420

Re: CV4003 / ECC82 types...

Mullard CV4003 have totally different construction with 'box plates' , copper grid posts and scalloped mica . Early Brimars had different contruction to ECC82 with short 14mm single anode support anodes . Later Brimar CV4003s , from memory , have the 17mm anodes and 1571 codes , which are the same c...
by nic
Tue Aug 06, 2019 10:10 am
Forum: Suppliers, recommended or not
Topic: Gintaras (Sakenas) website
Replies: 2
Views: 12662

Re: Gintaras (Sakenas) website

I went to order some parts . The website is now down . Looks like he is out of business