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DIY Stompboxes => Building your own stompbox => Topic started by: snk on April 09, 2021, 04:35:53 AM

Title: B337 & BC327 alternatives
Post by: snk on April 09, 2021, 04:35:53 AM
Hello,
I am considering building this (https://www.diyrecordingequipment.com/products/15ips-tape-saturation-colour-mkii), but i don't have any B337 & BC327 transistors... Are these models mandatory to have the circuit work at his best, or can I try several alternatives?
Which transistors would you recommend for this task?
Thank you

This is the schematic (https://cdn.shopify.com/s/files/1/0698/2265/files/15IPS_mkII_Schematic.pdf?v=1586643559)

(https://cdn.shopify.com/s/files/1/0698/2265/products/15IPS_Mark_II_Module.jpg?v=1565717896)
Title: Re: B337 & BC327 alternatives
Post by: antonis on April 09, 2021, 05:24:15 AM
BC546/547/548 (A/B/o C) for BC337 and BC556 to 560 (A/B/or C) for BC327..
Title: Re: B337 & BC327 alternatives
Post by: snk on April 09, 2021, 06:41:17 AM
Thank you, Antonis : I have plenty BC547!
Title: Re: B337 & BC327 alternatives
Post by: Jarno on April 09, 2021, 06:41:43 AM
That was my feeling as well, although I'd shoot for the "A" versions as 327 and 337 do not have a lot of gain. Only T1 and T4 might need to be a bit more "stout" since those are sort of the output to the stack of diodes, not sure if the small signal transistors can handle that (327/337 is a medium power transistor).
Title: Re: B337 & BC327 alternatives
Post by: antonis on April 09, 2021, 07:57:29 AM
Just make R6 value up to 1k, in case of T1/T4 are getting hot.. :icon_wink:

Title: Re: B337 & BC327 alternatives
Post by: Marcos - Munky on April 09, 2021, 12:55:02 PM
They're general purpose transistors. You can usually substitute them for a 2N3904 or 2N5088 (for BC337) and 2N3906 or 2N5087 (for BC327). Just keep in mind the BC and 2N transistors have different pinouts, they're reversed when compared to each other, so you need to rotate them by 180ยบ when you substitute a BC for a 2N or a 2N for a BC.
Title: Re: B337 & BC327 alternatives
Post by: iainpunk on April 09, 2021, 06:34:11 PM
i'd recommend BC547 and BC557, they are my main go-to transistors.

cheers
Title: Re: B337 & BC327 alternatives
Post by: snk on April 09, 2021, 06:54:13 PM
Thank you all for your suggestions!