In Search Of… (post the obscure parts you need help finding)

[finebyfine]

@JTEX Have you looked into using an LDO & Buck converter in parallel to switch over as the efficiency of one overcomes the other? https://e2e.ti.com/blogs_/b/powerho...rter-light-load-efficiency-with-an-ldo-part-1 or is the 17555 already more efficient than that?

 

[MBFX]

I am looking for a THAT4301, or detailed instructions (maybe with photos?) on how to use a different chip (THAT4305?) in the Muzzle. I really, really want to build this circuit.

Anyone want to name some reliable ebay sellers of Ge transistors and diodes?

 

[JTEX]

@JTEX Have you looked into using an LDO & Buck converter in parallel to switch over as the efficiency of one overcomes the other? https://e2e.ti.com/blogs_/b/powerho...rter-light-load-efficiency-with-an-ldo-part-1 or is the 17555 already more efficient than that?

The situation described in the TI paper does not apply to me. I don't need to switch between high and low-to-no load and be efficient in both situations. I'm always at a fairly steady, low load. Never just powered up with no load, when a low quiescent LDO might have lower losses than an idling buck converter.

I'm half thinking of making my own switcher optimized for that specific load. It would be too much work for just a few units though. The 17555 does look promising though. Waiting for the eval board. Luckily I have an old friend who's a field application engineer at Analog Devices. Just the guy I need

 

[Feral Feline]

I was actually looking for these КТ3102E I always been fond of, ran out a few years back and sellers on eBay are asking for an amount I'm not ready to pay for.. I ended up getting in touch with Yuriy from zahidprylad and he was able to find a thousands in their warehouse, just received enough supplies for a lifetime

I'm in search of Rusky Si NPN, got a URL for Yuriy?

 

[thomasbe86]

I’d use a 1N4148 before paying almost $4 a piece for a si diode at Small Bear. The FV is damn near

Diode comparison Yup, close enough, you got the I/V curve of loads of diodes here

 

[thomasbe86]

I'm in search of Rusky Si NPN, got a URL for Yuriy?

Yup, here it is

Западприбор - 25 лет опыта - официальный сайт - измерительные приборы самый большой ассортимент. >> Интернет магазин Западприбор

Ведущий интернет-магазин Западприбор - 25 лет опыта - официальный сайт: гарантия - 12 месяцев, наличие приборов на складе. Большой склад приборов: амперметр, вольтметр, ваттметр, частотомер, тормозной стенд, алкотестер, дозиметр, двигатель.

zapadpribor.com

They are located in Ukraine, it took about a month to get to Switzerland, but shipped within 24 hours

 

[PedalBuilder]

Yup, here it is

Западприбор - 25 лет опыта - официальный сайт - измерительные приборы самый большой ассортимент. >> Интернет магазин Западприбор

Ведущий интернет-магазин Западприбор - 25 лет опыта - официальный сайт: гарантия - 12 месяцев, наличие приборов на складе. Большой склад приборов: амперметр, вольтметр, ваттметр, частотомер, тормозной стенд, алкотестер, дозиметр, двигатель.

zapadpribor.com

They are located in Ukraine, it took about a month to get to Switzerland, but shipped within 24 hours

How was their pricing? Their website suggests that they have a very wide selection of ex-Soviet transistors, including some that are hard to source these days.

 

[thomasbe86]

How was their pricing? Their website suggests that they have a very wide selection of ex-Soviet transistors, including some that are hard to source these days.

I just contacted them at "detali at zahidprylad dot com dot ua" and they gave me a fair quote, I paid about 1$ for each. See how it compares to what you can find on ebay, giving that these KT3102E were sold out everywhere else I went for it. Supply and demand

 

[jessenator]

I see that Small Bear stocks 2SC1815 NPNs, but I'm wondering if someone has both them and the 2SK30A FET, just to keep shipping down (SB is sold out). Two of each. Thanks. I'm in the US.

Transistor FET 2SK30A-GR

New England's source for guitar pedals, pedal parts and electronics.

smallbear-electronics.mybigcommerce.com

 

[Erik S]

I see that Small Bear stocks 2SC1815 NPNs, but I'm wondering if someone has both them and the 2SK30A FET, just to keep shipping down (SB is sold out). Two of each. Thanks. I'm in the US.

Transistor FET 2SK30A-GR

New England's source for guitar pedals, pedal parts and electronics.

smallbear-electronics.mybigcommerce.com

Not sure if the suffix difference is a no-go on the FET...

2SK30 2SK30ATM-Y N-Channel 50V 6.5mA

TOSHIBA- Get It Fast - Same Day Shipping

www.taydaelectronics.com

2SC1815 C1815 TRANSISTOR NPN 50V 0.15A

KEC/TOSHIBA/GP/UTC - Get It Fast - Same Day Shipping

www.taydaelectronics.com

 

[jessenator]

Not sure if the suffix difference is a no-go on the FET...

2SK30 2SK30ATM-Y N-Channel 50V 6.5mA

TOSHIBA- Get It Fast - Same Day Shipping

www.taydaelectronics.com

2SC1815 C1815 TRANSISTOR NPN 50V 0.15A

KEC/TOSHIBA/GP/UTC - Get It Fast - Same Day Shipping

www.taydaelectronics.com

Thanks. I didn't even bother to check them, since most of their other R@R3 silicon and Ge has been sold out for ages. I'll be pleasantly surprised if they both turn out to be genuine Toshiba, but at that price I'm willing to experiment.

 

[owlexifry]

has anyone grabbed an OPA2134 from tayda recently?

mouser is out, digikey is out.

i bought a few from tayda a couple years ago when they were only like usd$4, and i can assume they were fine - two of them went in a blueshift build that works beautifully, but then this thread has me concerned about rolling the dice again...

 

[jwin615]

has anyone grabbed an OPA2134 from tayda recently?

mouser is out, digikey is out.

i bought a few from tayda a couple years ago when they were only like usd$4, and i can assume they were fine - two of them went in a blueshift build that works beautifully, but then this thread has me concerned about rolling the dice again...

Get them from TI

OPA2134 data sheet, product information and support | TI.com

TI’s OPA2134 is a SoundPlus™ Audio Operational Amplifier with Low Distortion, Low Noise and Precision. Find parameters, ordering and quality information

www.ti.com

$4.18

 

[darwin999]

has anyone grabbed an OPA2134 from tayda recently?

mouser is out, digikey is out.

I've not tried Tayda for OPA2134's, but...
Mouser has some coming in on January 8 (DIP-8 OPA2134PA and PAG4), for $6.
Also, AES has some at $5 https://www.tubesandmore.com/products/op-amp-opa2134-dual-high-performance-audio-8-pin-dip.
Finally, there's StompBoxParts at $5.75. https://stompboxparts.com/semiconductors/opa2134pa-precision-dual-opamp/

 

[bluedmc777]

Correct spec CV7112 for a Chicken Head build…but I haven’t really went down the rabbit hole of finding one. I assume it needs be around 75hfe and low leakage?

 

[darwin999]

I am looking for a THAT4301, or detailed instructions (maybe with photos?) on how to use a different chip (THAT4305?) in the Muzzle. I really, really want to build this circuit.

Buy a Muzzle Classic, plus a THAT4305 + retrofit module: https://www.pedalpcb.com/product/ic-that4301p20-u/
(Plus some pinheaders...)

 

[Bricksnbeatles]

I’ve got something a bit unusual I’m searching for…


Does anyone know of a knob in the 12-19mm size range that vaguely resembles the mellotron’s three main control knobs? So far I haven’t had any luck finding knobs that have a mirrored/metallic top insert and a raised plastic indicator running across the diameter. If anyone’s seen anything that might fit the bill, please lmk— LMS, AmplifiedParts, and Thonk have been a bust

 

[benny_profane]

Does anyone know of a knob in the 12-19mm size range that vaguely resembles the mellotron’s three main control knobs?

Pardon our interruption...

EDIT: These are bigger than you requested. I can’t find anything that small in the same style.

 

[jwin615]

I’ve got something a bit unusual I’m searching for…
View attachment 64361

Does anyone know of a knob in the 12-19mm size range that vaguely resembles the mellotron’s three main control knobs? So far I haven’t had any luck finding knobs that have a mirrored/metallic top insert and a raised plastic indicator running across the diameter. If anyone’s seen anything that might fit the bill, please lmk— LMS, AmplifiedParts, and Thonk have been a bust

Search eBay for vinyage radio knobs.
May get lucky. I've bought some in lots like that but most are for pots mounted under the face surface (not sure the technical term).
I'll check my stash tonight as see if I happen to have any that match.

 

[Bricksnbeatles]

Pardon our interruption...

EDIT: These are bigger than you requested. I can’t find anything that small in the same style.

Yeah, bummer they’re too big. Just starred them on eBay though, bc I might pick them up down the line if they’re still unsold when I start a digital ‘mellotron’ project I’ve been thinking about.
Doesn’t seem to be anything remotely similar at a smaller size, but I’m determined lol. Probably pretty telling though that the current mellotron company is using Fairchild style knobs now instead of anything resembling the classic.
Anyone know how much custom plastics molding costs?