With original late-70s Op-Amp Big Muffs selling for exorbitant prices, Mike Matthews decided to take the power to the people and reissue the classic pedal at a price that players could afford! The circuitry of the new Op-Amp Big Muff —sometimes also referred to as the IC or V4 Big Muff— has been faithfully re-created while several practical enhancements have been added including a compact, die-cast chassis
The Op-Amp Big Muff Pi features standard controls: Sustain, Tone
We want you to feel confident with your Prymaxe purchase, which is why when you purchase a new product from us, you are automatically enrolled into our FREE Two Year Warranty.*
What is covered:
What is NOT covered:
* We reserve the right to end this promotion at any time.
All in stock orders placed before 1pm EST will ship same day and all orders placed after the cutoff will ship the next business day*. If you need an order immediately, please let us know and we’ll try our best to accommodate your request.
Most orders shipping within the US will ship via USPS or FedEx and are fully insured, we also offer express options if you need an item within 24 hours. All tracking numbers will be sent via email after the item is shipped. If you did not receive your tracking number please feel free to call or email us.
All US Orders $49+ Ship for FREE
We love and truly appreciate all of our International customers. All of our international shipments are fully insured and are guaranteed to be delivered or your money back. We offer a variety of shipping options for you to choose from and if for any reason there is an issue with your order we will make it right, that is our promise you.
Pre-Orders typically ship with 2 weeks. In the event a product is backordered we will contact you with an exact shipping timeframe.
Smaller items will ship USPS First Class.
USA shipping only for Barber Electronics, Boss, Darkglass, Dunlop, DryBell, EarthQuaker Devices, Eventide, EVH, Fender, Gretsch, Korg, Marshall, Music Man, MXR, PreSonus, Quilter, Roland, Schecter, Shure, Source Audio, Way Huge, Tech 21, Vertex, Voodoo Lab, Vox, Wampler.
What if my package gets stolen?
Please note: We are a small, family owned business. While we want to make sure you are satisfied with your purchase, we would like to try to limit the amount of returns as much as possible. This helps both us and the customer save time and money. If you are unsure about a product, please contact us before you complete the purchase, and we'll do our best to find the item that will best suit your needs. Prymaxe reserves the right to define abuse of the return policy on a case by case basis and consequently refuse subsequent return requests by said abuser and place them "All Sales Final".
Last Updated: March 27, 2018
If you are not 100% satisfied with your purchase, you can return it within 45 days of the original purchase date for a store credit refund, or within 14 days of the original purchase date for a refund to the original purchase method (PayPal, credit card, etc). If an item is not received by us within the 45-day window, the package will be refused. All new items returned must be in BRAND NEW condition with zero signs of wear or use and must be returned in the original packaging with ALL materials (free/bundled items -- must be unused/unopened, warranty cards, plastic, pouches, manuals etc.). We reserve the right to charge an up to 15% restocking fee on any opened guitars, amps, or keys being returned.
Our 45-Day Satisfaction Guarantee covers brand new products only -- it does not cover used and clearance products (see below). It also does not cover items in the “What is NOT Returnable” list below. Please note: All actual shipping fees paid by Prymaxe will be deducted from your refund. This includes orders that qualified for free or subsidized shipping. Return shipping must be paid by the buyer. If you received a defective or incorrect item, please see our FAQ section below.
All Used and Vintage items come with a 48 hour approval period. Please contact us directly at email@example.com within 48 hours of receiving your product for us to set up a manual return for you. Be sure to include your order number and reason for return in the email. All Used/Vintage items must be returned in the same condition they were sent to you in, as well as include all materials that came with it.
All returns should be insured by the buyer and sent via UPS, Fedex, or USPS with tracking. Please do not write on or attach tape or labels to the product box (these will be refused) -- use a packing box to return the product. Attach a shipping label with the RMA number onto the shipping box. Packages without a valid RMA number on the outside of the box will be refused.
To request an RMA number, please email firstname.lastname@example.org. We do not issue RMA by phone.
When will I get my refund?
Once your return is received by us, your refund will typically be processed within 10-15 business days. It typically takes a few business days for all credit card refunds to be processed and reflected on your statement. This means it will take a few extra days for your refund to show in your account after your return is processed. Store credit refunds will be given in the form of a e-gift card which will be available for immediate use after it is emailed to you. Please note: All actual shipping fees paid by Prymaxe will be deducted from your refund. This includes orders that qualified for free or subsidized shipping. Return shipping must be paid by the buyer. If you received a defective or incorrect item, please see the next question.
What if I receive a defective or incorrect item?
If a product is defective upon arrival, or the wrong item was received, all the shipping fees will be covered by us and we will give you a store-credit refund on the original order. For defective items, Prymaxe reserves the right to refuse the return if we determine the reason for the unit failing was not covered under the warranty (i.e., if the item was damaged due to user fault or error). If you feel your item was damaged in shipping, please take plenty of pictures of the damaged box and item and immediately contact us so we can open a claim with the shipping company.
Please be very diligent with testing your defective item. Be sure to try other guitars, power supplies, cables, and amps. We also request that you take a video of the item not working. If we receive your item, test it, and find it to be working, we will give you a refund minus the cost of shipping both ways.
When must I ship my return?
Your return must be received by us within 45 days of the original purchase date for store credit, or postmarked by 14 days for a refund to the original purchase method (PayPal, credit card, etc). This means you must ship your return with enough time for us to receive the package within the deadline. If it does not arrive within 45 days, we will refuse the package. If you feel you sent the package within a reasonable time frame, but it arrived late due to the shipping company’s error, please immediately contact us to make an appeal before we refuse the package.
What if I pre-ordered an item?
If a pre-ordered item arrives outside of the 45 day window from when you ordered it, you will have 7 days from the arrival date to send it back for store credit.
Why was my package refused?
There are a number of reasons your package could be refused by us, including:
Can't go wrong with a classic!!
I like this muff size and 9v standard plug. Its an improvement over original huge muff size and 3.5mm power plug. The reissue op amp muff sounds really full, lots of harmonic content and a lot of sustain. Not great cleanup, and messy into driven amps, but you already know that if you look into vintage op-amp muffs. But really huge, clear and defined sound on clean amps. Sounds ok on bass but wouldn't use as main fuzz. On guitar really shines with tone at 11:00 for rhythm and at 1:00 for leads.
I've owned a few Muffs in my day (by EHX and others), and this is one of my favorites, maybe only trailing my sadly lost black Russian. It has a graininess to it, which is usually used as a bad term in pedals, but I say that because the transistor Muff can be so smothering, whereas this has a spikiness that allows individual notes to be a lot more pronounced.
Love or hate the Muff tone stack (I'm a fan--and I think it works well in the IC configuration here, more flexible and useful for smoothing out the sound when you roll the tone counterclockwise), the option to bypass it really opens the sound up, giving this pedal options, sonically, that some of its brothers don't.
Construction is great. 9v option is nice for those that like it. Price is ridiculous. Hard to find a fault here.