I've had my SWR Baby Blue combo since 2005. I've always found it to be a very versatile combo for practice, studio, and even some gigs. Over the years it's proven to be very well built but I remember it needed some minor modifications right from the day I bought it.
The first thing I had to do was pull the panel off of the back of the cab and silicone around both switches and seal the whole panel back to the cab with silicone. In addition to that I had to seal the speaker cable protruding from inside the cabinet to to the head to prevent a whistling when really pushing the 10" speaker.
I remember although the amp sounded great through other cabs I wasn't super happy about the tone of the combo. It did give a lot of value for the money and sounded good enough, so I kept it. It later proved to have an exceptional D.I. for recording and a wealth of other studio features I didn't know I'd be using down the road.
I found myself using it with a drummer on a regular basis and pushing it pretty hard. I wanted to run it at 2 ohms like the old Electric Blue heads could do. I thought I'd give it a try and install some fans to keep the amp cool.
Interior photo from TB member Duff2
This seemed to be the best location for the fans and two little ones spread out would serve the combo best as the vent on top was about the same width of the two fans. I was concerned about the fans inducing noise in the perfectly quiet studio quality pre-amp so wired them up to an independent supply out the back polarized to accept standard boss adapters.
They work exceptionally well. I tested them out with smoke to observe the air flow. They seem to draw air from the back venting on the amp and right out the top vents on the combo. I immediately noticed the amp running cooler with more headroom and 2 ohms hasn't been a problem. I think the old Electric Blue documentation states the amp to put out 220 W RMS at 2 ohms but I haven't confirmed that on mine. I can say the basic design and output transistors on the old ones vs the Fender ones were the same.
I happily used and abused this combo for years and then I came across this thread here on TB. I LOVE THIS SITE! SWR Aural Enhancer Bypass
If you follow through the thread you'll find details and how I performed the AE bypass mod on this amp. This mod was an amazing transformation of this combo. It was a prolific change for me and rekindled my love for this combo. It had been previously displaced by a Mesa Walkabout Scout.
Because the Baby Blue head has push pull pots all over I used a on/off/on switch to perform the bypass mod. This gave the mod one more dimension as I now have 3 separate voicings to choose from. The standard AE, the flat setting, and something in-between both. I'm finding I prefer the in-between setting most but I still use all three depending on what sound or function I'm using the amp for. I'll often use it as a powered P.A. monitor and the flat setting is great for that.
Switch down is stock AE, middle position is the in-between, and up is the flat setting.
As I found myself enjoying the Baby Baby Blue II combo so much more after this mod I began to think about what else I could do to it to improve on. Like I sad before, I was never really happy with the sound of the combo but it worked well enough. I started to look into replacing the stock P.A.S. speaker with something that could handle more excursion and perhaps lighten things up. A quick thread here in the amps forum and the brilliant minds of Talkbass directed me to use Linear Teams program WinISD.
There was a little bit of a learning curve with that program but I had successfully used it when searching for new speakers for my Traynor YC-610. I tried modeling any speaker I could find until I found an appropriate curve given the combos dimensions and port size. The best curve by far was given by the Eminence Deltalite 2510. It showed a flat response down to about 80 Hz and 65 Hz at -3 dB. The software said the cab would be tuned to 60 Hz but the plot didn't really depict a bump at 60 Hz or anything. I'm a little lost when it came to deciphering the data from WinISD but it was clear that the Deltalite 2510 was the best 10" available for this box so I ordered one.
*edit- using a car audio port tuning program on-line showed the port in this box being tuned to 48.5 Hz.
Let me tell you. This thing sounds good! I was blown away. Not only is it lighter (slightly) it's much more powerful, deeper, and more articulate. Pretty much better in any way I can conceive of. The stock driver struggled with the anything on the low b string. Not anymore. I was hammering this speaker and it just pounded out the deep end. I couldn't believe that little box could produce lows like that without some kind of trickery like the passive woofer on my Scout cabs.
Just to make perfectly sure my ears didn't deceive me I put the stock PAS driver back in....
It was at this time I realized that Fenders marketing group must have been behind the creation of this combo and without anybody who cares about the reputation of SWR on the team, this combo was thrown together without any R&D. Although I think they were a little ahead of their time, I don't think they ever modeled this cab with the driver specs from PAS. If they did, they would have seen it's not properly matched at all. The PAS driver info from the Golliath III series is not available on line but I'd love to get my hands on it just to see what it would plot out to be.
In comparison, the PAS driver seemed like a mid driver with subtle low end. With the stock setting, SWR's AE circuit always in place, there was always a 250 Hz mid reduction. This just seemed to pit the amp against the combo and the resulting sound had some audible low end bass only because of the mid reduction. The AE bypass mod allowed the PAS drivers natural tones to come out which is why I may have liked the AE bypass mod so much. The Delta 2510 really brought this cab into the bass guitar world. It's no surprise to me that this amp has been discontinued and the Spellbinder has replaced it loaded with an Eminence speaker and an AE bypass function.
If you are one of the happy owners of these fine amps and not so fine combos, you can perform a few mods to the combo and end up with a world class portable rig. The used market doesn't call much for these and I can kind of see why now. The price of a Eminence Deltalite 2510 is a little hard to swallow these days however, IMO it was worth every penny.
Next I'd like to look into replacing the tweeter as the LeSon was IMO the weak link in the chain from the first day I bought it. I had no idea the PAS driver was the real weak link. If any of you have any suggestions for a good tweeter that would fit in this combo please let me know. If you've got down this far thanks for reading!