BQFS Vintage 70s Pre-EB MusicMan Stingray 2-Band Preamp - 1 Year Warranty! - 2026

Vintage Stingray Tone — BQFS Pre-Ernie Ball 2-Band Onboard Preamp

Hand-built by a retired electronics tech with over 50 years of experience.

EASIER INSTALLATION IMPROVED VERSION USING SCREW-TERMINALS - ONE-YEAR WARRANTY PARTS & LABOR!

Latest Upgrade - Tantalum Capacitors in the signal path for better tone quality.

Over 100 Sold - No Failures!

Classic Stingray Sound. Modern Reliability

If you’ve ever played a Sterling by MusicMan, OLP bass, or any other MM-style bass and wished it had the growl, sizzle, and punch of a vintage Stingray, this preamp can be part of your solution. I’m a retired electronics technician with lots of experience modding basses and amps, and I built this preamp to faithfully recreate the tone of my beloved '79 Stingray.

I built the first version of this preamp back in 2013 to replicate the classic tone of my '79 Stingray—after being disappointed by the stock electronics in my Ray4. I was about to undergo the first of five back surgeries, and needed a bass that weighed less than 10 pounds, so I bought a Ray4, but soon found out some drawbacks.

The ceramic pickup was too hot, and the preamp lacked finesse and was easily driven into distortion. So I upgraded the pickup with a Nordstrand MM4.2 and built a faithful clone of the original pre-EB Stingray 2-band preamp.

I ended up selling the bass, as I generally just play 5 string basses these days. The woman who bought it had this to say - "The tone is incredible. Bud did a great job defretting the neck and wiring up the preamp and Nordstrand 4.2. This thing is a beast."

Since that upgrade worked so well, I decided to upgrade a couple of other Sterling Ray5s, using the same preamp and the Nordstrand MM5.2. Fabulous results!

What makes this preamp special?

• ✅ Authentic Stingray EQ curves: Treble (+20dB/-16dB @ 10kHz), Bass (+14dB/-7dB @ 40Hz)
• ✅ Modern NJM4250D op-amp: Long battery life, no tonal compromise (identical specs to the LM4250 used by Leo way back when)
• ✅ Modern high-quality components: Smaller footprint, higher reliability, same vintage tone
• ✅ Tantalum capacitors in the signal path for improved sonic clarity
• ✅ Screw terminals: Easy installation, flexible mounting
• ✅ Two ground terminals: One used for the jack ground, the other unused for convenience
• ✅ Fully assembled & tested: No soldering required (in many cases)
• ✅ Includes all pots, jack, battery snap, and detailed documentation
• ✅ One-year parts and labor warranty
• ✅ Circuit and Printed Circuit Board both designed and built in the USA

Technical Overview:

Treble Control (+20dB/-16dB @ 10kHz): By design, there is more treble boost than treble cut. This gives it that "sizzle" associated with the Stingray.

Bass Control (+14dB/-7dB @ 40Hz): The boost curve rises towards the lower frequencies without flattening out at any frequency. The cut response is shelving, flattening out at 30–100Hz when fully cut.

As you can see, the preamp is not at all typical—there is no "center detent" on either treble or bass control as there is no actual center point. Leo Fender designed it this way for optimum response coupled with his custom-wound Alnico V pickup.

Volume Control: Rather than run the output of the pickup directly to the volume control, which would adversely affect pickup loading and frequency response, the control is placed last in the circuit's signal path, right before the signal goes to the output jack. This way, the entire pickup response reaches the preamp. This provides a high impedance load on the pickup while providing a low impedance output to your pedal board or amplifier input.

I include everything you need for installation, including:

• 25K linear pot (volume)
• 100K audio taper pot (bass)
• 1M reverse log pot (treble)
• Battery snap connector
• Stereo jack for auto power switching
• Pre-soldered wires and socketed op-amp for easy installation and allowing for some limited experimentation
• Exact same components as the late 70s original designed by Leo Fender
• Battery life in use will equal the battery's shelf-life as the current draw is extremely low.

I use the NJM4250D op-amp, a modern equivalent to the original LM4250, offering similar low-current performance and tone. As a bonus, the op-amp is socketed for easy experimentation. Try different chips for different tonal shaping.

It is vital to know that in order to truly recreate the vintage Stingray tone, this preamp must be paired with a pickup wound to the exact same specs as Leo's Alnico V pickup. Today, there are only three pickups I know about which totally nail this spec and produce this tone.

My favorite is the Nordstrand MM series. There is also the Aguilar M series, and the Guitar Fetish (four string basses only) MM-Pro with Alnico V magnet structure.

This preamp is great for players who want to upgrade their budget Stingray-style bass without guesswork or major expense. No matter the bass you are modding, this preamp delivers the tone and quality you’ve been looking for.

⚠️ I do NOT accept returns or refund requests as it is way too easy to damage the preamp if you have little to no experience working with sensitive electronic circuits.

I also include very detailed documentation with the preamp including diagrams and pictures. If you would like to read it, copy and paste this into another browser tab. 

Unlike other sellers, I DO provide a ONE YEAR warranty on both parts and labor. The only cost to you will be covering shipping in both directions (usually $10 or less).

Please note that returns for service must be approved before you send the unit back. If you use or change parts (other than the I.C.), or solder on the board itself, that will VOID the warranty. Changing the pots or changing the I.C. is okay. If the preamp doesn't work, or stops working then you must send EVERYTHING back. That way I can send you back a unit that works properly and is all ready to be reinstalled.

If you have any questions, or need to see more pictures, please ask before bidding, making an offer, or buying.

Thanks for looking, and don't forget to check out my other bass-related stuff!