When I started Studio Electronics in 1981, acquiring a large inventory of semiconductors was a big priority. I began by filling about 20 tackle boxes with all the semis used in the MCI-Sony, Ampex, Harrison, API, Crown, and other products that I often serviced, and carried with the tools and test gear I kept in my car. When doing on-site service calls I dreaded getting stuck on a job and having to return for lack of some small part, so over the years I obsessively kept adding semi’s. And I duplicated all the inventory in my workshop, to avoid parts runs to the car when doing bench work.

As my business expanded in the 90’s and 00’s we dedicated a large section of our shop to semiconductor inventory and added new sections for EMT, UREI, Eventide, and AMS. In some cases this required painstaking detective work. And in the last ten years I’ve bought out inventory from several local shops that closed. As I write this in 2018, we have a massive, very complete semiconductor stock that includes at least 99% of the parts ever used in analog and digital audio, and other consumer and industrial electronics applications.

David Kulka


• Our semiconductors are organized into sub-categories, by the part number prefix. In most cases, these prefixes (such as 74LS) define a family of devices. Be aware that in some cases the same IC family used two different prefixes. (For example, 4001 and MC14001 are the same CMOS logic chip. LM741 and 741 are the same opamp, and 2SB560 and B560 are the same transistor.) In cases like this we’ve added notes to the subcategory pages but when you search, be aware that the part number on a schematic or on a part might be listed in a slightly different way on our store.

• Part number suffixes can also differ for items that are functionally identical. Usually these suffixes identify the package material of a part, not its internal circuitry or specs. Some manufacturers use “P” at the end of a part number to indicate plastic packaging, while others use “N”. “B” at the end of a part number can refer to a ceramic package. The suffix in a part number is rarely a concern and most experienced technicians ignore them when replacing parts. To avoid confusion, we’ve listed most parts with no suffix, even if one is marked on the package. Almost all IC’s have plastic packages and unless otherwise specified, the buyer can assume that an IC is the standard black plastic type. We’ve ignored package material designations in almost all our listings.

• In almost all cases, our parts are listed by their basic, generic part number.

• There are no photos in most of these listings, but we do indicate package type. In almost all cases the generic part number shown will be enough to match the part you need, but to confirm a correct match, click on the listing and check the package type in Overview section.

• About 90% of these items are from major manufacturers like Texas Instruments, Motorola, Dallas, Fairchild, Hitachi, National, NEC, etc., but some are unbranded or from minor manufacturers. All parts are unused and fully guaranteed. Some older parts show age from long-term storage, but this will not affect proper operation. None of our parts are counterfeit or B stock.

• Some special OEM parts are listed under the manufacturer category, not with the other semiconductors. For example, most Avalon, Sony, Crown, and dbx semiconductors will be found in those categories, and not this one.

• You can always use the search box to find a specific part, but use the basic, generic part number, with no prefix or suffix.

• If you can’t find what you need, please ask. Contact us.

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SKU: TMS27C512
Texas Instruments TMS27C512 28-Pin EPROM IC, Guaranteed.