T ere are several types of BBDs and Clocks t at work wit t e ABDX
The ABDX accepts d fferent types of BBDs and the r clock counterparts. The follow ng chart llustrates the advantages and d sadvantages of each. Note that the
Clock type does not contr bute to the pros/cons. They are s mply the appropr ate ch ps to use n each c rcumstance.
BBD Clock Steps Pros Cons
MN3005 MN3101 4096 Best sound ng. Can run at up to 15v for added
headroom
Out of product on, rare, hard to f nd (up to $80 for a pa r)
MN3205 MN3102 4096 Also great sound ng. Lower current consumpt on than
the MN3005
Out of product on, rare, hard to f nd. Requ res lower voltage to
operate.
MN3008 MN3101 or
MN3102
2048 Sounds every b t as good as the MN3005. Can be run
up to 15v (MN3101 only).
Out of product on, rare, hard to f nd. Half the delay t me of the
MN3005.
BL3208B BL3102 2048 Very good alternat ve that s currently n product on.
Low current consumpt on. Used by EHX for some of
the modern DMM.
Half the delay t me of the MN3005, MN3205 and v3205.
V3205 V3102 4096 Cheap. Same delay t me as the MN3005. Worst sound ng. Lower headroom than the BL3208B even
when operated at nearly the same voltages.
Th s chart pretty much expla ns the order n wh ch you should choose your BBD type from top to bottom. If you can f nd the MN3005 and afford t, then use t. If you
are l m ted to current product on ch ps, then choose between the super or sound ng BL3208B w th half the delay t me or the nfer or v3205 that w ll g ve you a full
500ms of delay from the ABDX.
Please keep n m nd that these evaluat ons are n degrees, not absolutes. IOW, t s ent rely poss ble to bu ld the ABDX w th the v3205 to get the max delay and st ll
get a very acceptable amount of f del ty (the des gn has mods to help w th th s). It’s just never go ng to sound as good as the MN3005 runn ng at 15v, per od.
The great th ng about the ABDX s that you can change the ch ps out at w ll s mply by chang ng two jumpers on the board. So, you m ght bu ld t w th a BL3208B or
v3205 now, and then replace them w th the MN3205 or MN3005 later f you are able to source them. It’s that s mple (you w ll have to re-cal brate the delay when
do ng so).
Note: I have not personally tested the MN3205 w th the Aquaboy for the s mple reason that I have never found any leg t mate ch ps. I have tested all other
conf gurat ons.
A word about sourcing BBD c ips
Whenever you try to locate and purchase out of product on ch ps l ke the MN3005 and MN3205 you are runn ng the r sk of gett ng r pped off, e ther through mal ce
or gnorance on the seller’s part. There are a lot of fake ch ps out there and qu te a few sellers that make a l v ng by sell ng counterfe ts to hapless gear geeks l ke
us. So, use caut on. Don’t just throw money down the to let at whatever As an eBay seller cla ms to have a true MN3005 because most l kely t s a fake. Rather, f
you want to get these ch ps, ask around on trusted forums. There are some fellow DIY’ers that may be w ll ng to part w th some of the r stash from t me to t me or
po nt you toward a rel able source. It takes t me but t’s also worth the effort.
