This listing is for replacement pre-amps for vintage 70s-80s Matsumoku Aria Pro II SB-1000 basses. These pre-amps are straight swap replicas of the original circuit using identical design values but with the improvements of using modern precision components and high-quality PCB manufacture. The pre-amp was also found in the very limited SB-R150 and SB-800 basses in addition to the virtually unknown NK-700/800 series of guitars.
The components in the original Aria Pro II pre-amps are now 28-37 years old and many have either already expired or are subject to the effects of component aging and inevitable performance degradation. These original pre-amp circuits were never made available as aftermarket replacements meaning many vintage SB-1000s end up gutted of their active electronics or fitted with an alternative pre-amp. Without the original circuit these basses lose that versatile and distinctive SB-1000 sound. If you are wanting to restore missing components, send me a message and I will see if I can help.
This is the 10-pin "v1" BB Noisekiller pre-amp design which was fitted to both the sought-after 1978-80 "batwing" basses and the later 80s models. Like the originals they are simply a plug-and-play design that only require that the connector be pulled from the old unit and pushed onto the connector on the new one.
In the decades since the original SB-1000s were issued, the quality and availability of premium grade components has improved for the better immensely. In addition to the circuit being an exact reproduction of the original design, the pre-amp has been upgraded with top-quality components. This does not alter the intrinsic sound of the pre-amp, but increases reliability and performance. The main upgrade is the integrated circuit amplifiers themselves. After testing and comparing several perfomance chips from various manufacturers we opted to use the fantastic Burr Brown OPA2277. For true vintage reproduction purposes the pre-amps are also available fitted with JRC4558 chips as per the original. The upgraded version benefits from a modern IC's high performance specification, primarily offering lower current consumption, a remarkably superior noise floor and lower signal distortion characteristics; importantly none of this alters the fundamental sound of the pre-amp. In addition to the IC upgrades, overall quality has been raised through using precision metal film resistors, premium Japanese capacitors, turned pin IC sockets and heavy copper PCB traces with an extended ground plane for higher noise rejection.
IMPORTANT SHIPPING NOTICE
Due to a recent problem with a fraudulent buyer gaming the dispute system, we are no longer able to offer an economy shipping option; we would rather that our customers not have to pay additional costs simply because of one unscrupulous eBayer however we don't have much choice. Instead of passing the entire €13+ cost of tracked international shipping to our customers, we've decided to go halfway. The flat shipping cost listed covers half of the actual cost, we'll absorb the rest until we can find a more economical shipping option. If you are an eBay seller yourself, we'd recommend that you cover your back against fraudulent buyers claiming non-receipt by going for tracked services every time. Losing both an item, a sent replacement and the original payment is not worth the risk.
Product FAQs
Q. Can I upgrade a passive bass to active using these preamps?
A. Yes. The only caveats being that you will need to swap out your volume and tone pots to lower values (20-25k) and fit a switched DPDT jack socket to manage the 2x 9v battery supply. A Molex KK or TE CST-100 connector is all you need to fit the pre-amp. These are available from electronics suppliers or here on eBay also. You will of course also need space for the batteries and pre-amp which are generally not as easy to acquire!
Q. Can the pre-amp be run on a 9v supply?
A. Yes and no but mostly "no". The pre-amp works on a balanced supply hence the two batteries. Whilst it is possible to fudge a solution to use only one battery, the impact on the noise cancelling capability and overall signal headroom make the negatives outweigh the positives.
Q. I bought my bass with the pre-amp missing. Which way around do I fit this pre-amp?
A. The three pins marked "PWR" on the pre-amp PCB correspond to the three wires that supply voltage. These are most commonly red/orange/blue from the outside in. The red and blue wires should lead to two of the jack socket tags whilst the orange leads to the batteries.
Q. My bass has been completely gutted! Can I buy new pickups, electronics, etc?
A. Ouch. Well, new pickups can be bought from Rautia Guitars (http://www.rautiaguitars.net/aria-pro-ii.html) here in Finland, Aaron Armstrong in the UK (http://www.armstrongpickups.co.uk/) or Reed James in the US (http://reedjamescustom.com/id22.html). We prefer Rautia Guitars' reproductions as they match the originals the closest and are a good price. The electronics are a bit more difficult. The stacked pots in the 1981-1986 SB-1000 are impossible to buy outside of a custom order of a few thousand (!!) however we can make them up manually from standard stacked pot wafers. The varitone and rest of the electronics loom can be reproduced also. The downside is that the complex nature of the electronics means this is not a cheap proposition. PM me. 1977-1979 SB-1000s (active only) were much simpler and can be reproduced using standard components. Again, PM me.
Q. Do you have any of the original knobs for sale?
A. No. The originals are near-impossible to get ahold of now. Occasionally they pop up on eBay for ridiculous prices! So much so, it is often almost as cheap to buy a low-end Aria Pro II bass from the Matsumoku era just to get the knobs off it. Crazy world!
Q. My battery LED circuit is causing clicks in the audio. Is this normal?
A. No, or at least it is not what is supposed to happen of course. Component aging causes components such as the capacitors to leak current or other unwanted things. The upshot of this is that the LED blinker circuit (the one wrapped in electrical tape!) injects noise spikes onto the pre-amp supply, which is then pushed onto the audio signal as clicks or "pulses". We are considering a special version of the BB pre-amp which incorporates a "soft LED pulse" circuit. This would allow the original faulty circuit and LED to be removed and a new low-current LED to be fitted in its place. Let us know if you would be interested in this!
Customer comments:
- "[the pre-amp] opened up [the bottom end] drastically and is a lot less muddy than with the original BB preamp. The high mids and highs are a lot cleaner as well"
- "I thought something was wrong because it was almost silent compared to how it used to be. I almost **** myself because I turned [the amp] right up before I played it!"
- "I haven't used the [rotary] switch for years after the old one crapped out on me and I forgot how deep the bass sounds
As per the originals, pre-amps are epoxy potted in an ABS case to protect the circuit from environmental damage. Pre-amps are supplied with an unkeyed 10-pin header. Do ensure that the pre-amp is oriented in the same direction as the previous unit when plugging in the connector, ie. PCB the same side of the connector. The listing photographs show a new unit and an original in the same alignment. All pinout labels are printed onto the PCB however confirmation of orientation can easily be made via email if you want to send photos.
1978-1980 "batwing" SB-1000 circuit
1980 onwards 10-pin SB-1000 circuit
