OC75 is this a fake?
- Thread starter Johnnyorange500
- Start date
szukalski
Well-known member
I'm no expert on the accuracy of such stuff.
All I can say is that most of the professionals stopped trying to look for these sorts of things long ago. You want it to be true, you hope it can be true, maybe it is. More likely it's not. Even if it is, it's likely to have been tested and rejected by those who know.
All I can say is that most of the professionals stopped trying to look for these sorts of things long ago. You want it to be true, you hope it can be true, maybe it is. More likely it's not. Even if it is, it's likely to have been tested and rejected by those who know.
Johnnyorange500
Active member
Nicely put! Curiosity killed the cat!! Eh.. I'm going on a gut feeling there’s just something about the case that’s too clean. But like you said who knows? I’m no expert either.
cooder
Well-known member
More importantly: how does it measure? Have you got one of those cheap component testers that can give at least a first idea what's going on?
Something like this ( I use one and it's good mileage for the money IMO):
https://www.ebay.com/itm/4012787553...p/pnvdfjp4tPLVHQbGlMVFtw==|tkp:Bk9SR8qrroDTYg
Something like this ( I use one and it's good mileage for the money IMO):
https://www.ebay.com/itm/4012787553...p/pnvdfjp4tPLVHQbGlMVFtw==|tkp:Bk9SR8qrroDTYg
Johnnyorange500
Active member
Johnnyorange500
Active member
Soon find out! Yeah, defo agree. I’m just a sucker for these things. I like to know! I’m trying to work out the serial numbers but can’t work them out. Cheers
PedalBuilder
Well-known member
Who’s the seller? Lots of us here have bought germanium transistors off of eBay and can tell you if we’ve had positive or negative experiences with the seller. It’s also worth asking yourself if you really need an OC75 or if you need a transistor with a certain gain/leakage. It’s a lot easier and cheaper to find Soviet transistors that land in the right gain/leakage bucket than it is to find a western equivalent that hits the right gain/leakage bucket. Looking at what’s on eBay right now, you can get something like 40 Soviet MP21Ds, all of which are likely to work well in multiple classic fuzz circuits, for the price of one OC75 which may well be too leaky or have insufficient gain to work properly in any circuit. The Soviet stuff is mostly coming out of sealed boxes, the western stuff is mostly rejects that have been picked over by decades of pedal and radio builders and rejected by them for a reason.
coltonius
Well-known member
There’s a difference between searching for a hoard for mass production and a handful for personal use though.
Johnnyorange500
Active member
Nice find!! Things are looking up then!
Big Monk
Well-known member
When I ordered a big lot of OC75 a few years back, it was from Retroamplis in Spain and they were PRIME examples for the MK II.
I took a chance on 20 at almost $10 a piece and quite literally made 6 prime sets for the MK II.
Unfortunately, their stock seems to have dried up.
I believe I flipped that investment of $200 for almost $300 after measuring out the sets, and that includes me keeping a prime set.
I took a chance on 20 at almost $10 a piece and quite literally made 6 prime sets for the MK II.
Unfortunately, their stock seems to have dried up.
I believe I flipped that investment of $200 for almost $300 after measuring out the sets, and that includes me keeping a prime set.
Mcknib
Well-known member
It looks real to me
What I can tell you is it was made in Southampton the 45th week of the year 1971
7145DG =
71 = 1971
45 = 45th week of the year
DG = Southampton
What I can tell you is it was made in Southampton the 45th week of the year 1971
7145DG =
71 = 1971
45 = 45th week of the year
DG = Southampton
CV NUMBERS AND UK MILITARY DATE AND FACTORY CODES
I have just received an e-mail asking for details of military valve markings so here's a little primer for anyone who might have a similar interest. Valves used by the British military Armed Services were marked with a CV or common valve name which was defined by the Inter-Service Technical...
mullard.org
Johnnyorange500
Active member
Cheers dude!! Mullards to my ears!!It looks real to me
What I can tell you is it was made in Southampton the 45th week of the year 1971
7145DG =
71 = 1971
45 = 45th week of the year
DG = Southampton
CV NUMBERS AND UK MILITARY DATE AND FACTORY CODES
I have just received an e-mail asking for details of military valve markings so here's a little primer for anyone who might have a similar interest. Valves used by the British military Armed Services were marked with a CV or common valve name which was defined by the Inter-Service Technical...mullard.org
Mcknib
Well-known member
Mullards where made in lots of different places Holland, France, Germany etc UK made ones are labelled made in Great Britain anything made anywhere in the then British empire will say British made
Lots of genuine Mullard transistors do not even have Mullard written on them yours doesn't say Mullard because it was made for them by Associated Semiconductors
These for example are OC44 simply labelled POIF made for the post office at Mitcham in the 40th week of 1969 as you can see
If there's a code on them there's a fair chance they're genuine
Lots of genuine Mullard transistors do not even have Mullard written on them yours doesn't say Mullard because it was made for them by Associated Semiconductors
These for example are OC44 simply labelled POIF made for the post office at Mitcham in the 40th week of 1969 as you can see
If there's a code on them there's a fair chance they're genuine
Johnnyorange500
Active member
Thanks for all the great info. Much appreciated. Cheers buddy.
Mcknib
Well-known member
No problem I got a lot of info fromThanks for all the great info. Much appreciated. Cheers buddy.
Mr Transistor (Andrew) here
Mister Transistor's Vintage Technology Pages
Mister Transistor's Vintage Technology Pages
www.wylie.org.uk
He's pretty good at answering enquiries and very knowledgeable although the sites a bit of a mare to navigate there's lots of information on it
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