Looking for a Motorola MC3476P Op-amp Equivalent  - Page 1
Forum section: electronics / repair

author: Timmox
author_rank: Contributor
timestamp: July 03, 2025, 01:15:57 pm
content: Hi All,I'm working on a vintage 1970s active bass guitar that has a missing op-amp. It should have 6 in total that are all Motorola MC3476P. These seem to be discontinued so was wondering if anyone could suggest a good replacement.I found a document online that said an RCA CA3094E is an equivalent. I asked a seller on ebay if this was true but they were unsure.Any advice would be grateful received.Cheers,Tim.

author: fzabkar
author_rank: Super Contributor
timestamp: July 04, 2025, 09:31:42 pm
content: http://www.bitsavers.org/components/motorola/_dataBooks/1976_Motorola_Semiconductor_Data_Library_Volume_6_Series_B_Linear_Integrated_Circuits.pdf(datasheet for MC3476P1 on page 166)https://lcsc.com/datasheet/lcsc_datasheet_2412091020_onsemi-MC3476P1_C4369205.pdfFWIW, this is NTE's equivalent:https://www.rxelectronics.sg/datasheet/5e/nte944m.pdf(NTE944M)https://www.experimentalistsanonymous.com/diy/Datasheets/CA3094.pdf(CA3094E datasheet)The CA part is not a drop-in replacement.This supplier has stock:https://www.rocelec.com/part/01t4w00000PPiY0AAL-MC3476P1

author: Timmox
author_rank: Contributor
timestamp: July 05, 2025, 08:51:56 am
content: Thanks for your help fzabkarI'm in the UK so ordering from the USA is expensive and has a long delivery time.Is the NTE944M a drop in replacement?Should I order this:https://www.ebay.co.uk/itm/364327675356?_skw=NTE944M&itmmeta=01JZCW5EMXHW8D4Q3YWH4SZB8Q&hash=item54d39f25dc:g:8rYAAOSw42Zknnv0&itmprp=enc%3AAQAKAAAA4FkggFvd1GGDu0w3yXCmi1cKFN5VqtSg7V7LSqm7ZPnE62P9FYd60R73JyagjuBiMtChqzN4yNTBoX1%2F4h0OBrEdLXpFoBd6gzxgIfTuN5c5gyS5qHHPA%2FWWNQdEOSGj4brfRNLQeJWIwQzS6Z0%2B7eBMt5rkpglmaHBsgb%2FtiKTItGo6mjiUXZjdkpFuIGeQ1O8OB3VY8RPboNKWziZb53QFKq4s0gqSakUkh6AOUC07MGsGsc9SVKqGxvoqXishodyCO7JePiPahz7OL3EDjVtPoMqw7dLH7bBvAnXnhaqS%7Ctkp%3ABk9SR8LrlZz7ZQ

author: fzabkar
author_rank: Super Contributor
timestamp: July 05, 2025, 04:59:39 pm
content: I would wait for others to offer their advice. NTE parts are a last resort (because of ridiculous pricing). I don't trust eBay for ICs, anyway.

author: edavid
author_rank: Super Contributor
timestamp: July 05, 2025, 06:54:38 pm
content: CA3094 is definitely not compatible.However, uA776 and MC1776 are more available and are the same chip.I would probably order those from utsource and hope they were genuine:https://www.utsource.net/itm/p/11710238.htmlhttps://www.utsource.net/itm/p/48947.htmlOh, wait, do you only need one? In that case eBay might be cheaper.Or if you can establish that the Rset is fixed, you could patch in a normal op amp. That wouldn't be worth the effort for six ICs, but may be the easiest solution for just one.

author: fzabkar
author_rank: Super Contributor
timestamp: July 05, 2025, 08:05:29 pm
content: Quote from: edavid on July 05, 2025, 06:54:38 pmThey both cross to NTE888M:https://modularsynthesis.com/kuzmin/polivoks/NTE888M.pdfDoes that mean that there are minor differences?

author: David Hess
author_rank: Super Contributor
timestamp: July 05, 2025, 09:17:50 pm
content: The MC3476 is a programmable 741. You might be able to replace it with just a 741 depending on what the Iset current to pin 8 was. There should be a series resistor to pin 8 which well tell you how it was configured.Unfortunately programmable operational amplifiers are rare today, so I am not sure there are any modern replacements.

author: Timmox
author_rank: Contributor
timestamp: July 07, 2025, 09:57:07 am
content: Hi edavid,Do you think this will do the job? The seller is in the UK and the price seems reasonable. I understand ordering parts from ebay is a risk but I don't mind gabling £10 on this one.Cheers,Timhttps://www.ebay.co.uk/itm/191922032411?_skw=UA776CN&itmmeta=01JZJ4C6FJAYAKY8R6FW7MWTB2&hash=item2caf71cf1b:g:7cIAAOSwRVRmvIJB&itmprp=enc%3AAQAKAAAA4FkggFvd1GGDu0w3yXCmi1e4AjEx5EU22pC2cfRHkRlpryjUR%2FXfIZ%2BJtdqHifnIIqPKYo4%2FM8x3H0tpCxRQIBCIVg8lJ6VTt4ycDB9E3oyyDk8iUfXF8T1t9PXh%2Bc%2BStbz08A84dtF1Iey9wFyPHZ4a2qb29yUR2DnqF%2BU6kdSFxoyeFWp9ti5R6Fz%2FjIu7KmqHqWL5dxtEbZMiEtysx58ILxamCWxrC8VQICdhVgzsMizJUYY6sJpp5vJ7YtjUTaLwpr89vRXCYkOD4fzSahKUuXmMNN85pHDvfrK9w3d9%7Ctkp%3ABk9SR_zosMT8ZQ

author: edavid
author_rank: Super Contributor
timestamp: July 07, 2025, 12:07:07 pm
content: Quote from: Timmox on July 07, 2025, 09:57:07 amYes, looks fine (and returnable).