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Ampeg BA-108 Coffeeshop Micro Rig
- Thread starter Woodstockz
- Start date
Mine isn't blocked. Is there any chance you have put the grill cloth frame on upside down so that the Ampeg logo is blocking the port?
Now I'm thinking it was a 2nd and that screwup was why. Also why it looks mint (because it is), and GC sold it as used.
Edit: Someone had removed the badge and relocated it to the opposite corner. The holes are still there from the original location. Weird. Why do that? I'm getting some definite buzzing when playing the bottom string (4 stringer) - volume on 4. Speaker blown? Sounds good otherwise. I pulled the speaker and measured the cabinet internal volume at 0.68 cu ft. Winisd says it is tuned to 70Hz.
Edit: Someone had removed the badge and relocated it to the opposite corner. The holes are still there from the original location. Weird. Why do that? I'm getting some definite buzzing when playing the bottom string (4 stringer) - volume on 4. Speaker blown? Sounds good otherwise. I pulled the speaker and measured the cabinet internal volume at 0.68 cu ft. Winisd says it is tuned to 70Hz.
You may have the poorly glued front baffle problem as described in the BA108 with EMINENCE ALPHA 8 forum. A bead of glue fixed it in my case. But then I also took additional steps to secure it in case the glue didn't hold out.
http://www.talkbass.com/forum/showthread.php?p=13778556#post13778556
Yeah I can feel the baffle moving some along the top.
Looks like folks swapping in the Alpha 8A with success. I'm sort of liking the looks of the Celestion TF0818. Same price and maybe 3dB more sensitive.
These are in 1W/1m in a 0.68 cu ft box @70Hz:
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I measured TSPs on the stock BA-108 driver and the Celestion TF0818. Here's an WinISD plot of the BA-108 with three drivers:
I installed the TF0818 and tuned the cabinet to 55Hz with a removable port screwed inside the stock port. I haven't made measurements but the bottom end is much improved. Before the swap I was getting farting from the stock driver. Now I am getting the buzz from the cabinet I have yet to fix.
- Stock driver @ 70Hz
- Celestion TF0818 @ 55Hz
- Eminence Alpha 8A @ 70Hz (published TSPs)
I installed the TF0818 and tuned the cabinet to 55Hz with a removable port screwed inside the stock port. I haven't made measurements but the bottom end is much improved. Before the swap I was getting farting from the stock driver. Now I am getting the buzz from the cabinet I have yet to fix.
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has this ever happened to anyone else?
I use headphones with my BA-108 a lot of the time. At least 3 times now it has happened that after I unplug the headphone jack the signal still does not come through to the speaker. I presume this is something to do with the cut-off switch within the PCB mounted headphone socket.
This was disturbing the first time it happened but I eventually jammed the headphone jack in and out a few times and the signal came back. Another time the signal only came partly back and then faded away again.
Does anyone have any idea what would be causing this?
I use headphones with my BA-108 a lot of the time. At least 3 times now it has happened that after I unplug the headphone jack the signal still does not come through to the speaker. I presume this is something to do with the cut-off switch within the PCB mounted headphone socket.
This was disturbing the first time it happened but I eventually jammed the headphone jack in and out a few times and the signal came back. Another time the signal only came partly back and then faded away again.
Does anyone have any idea what would be causing this?
Unlikely. The BA-108 is only a few months old and lives inside. The headphone jack is even younger.
Doesn't matter. They travel by ship to America. Salt water, you know? Not saying that's for sure the problem, but worth a shot.
Good suggestion. I might try squirting some CRC contact cleaner down the headphone socket.
On to the next project. This one is done.
I recommend super-thin CA for gluing the seams.
I don't think the front baffle was glued at all except for maybe at the wood blocks. The super-thin CA has a water-like consistency. Due to the tight joint fit it wicks into the wood and kicks off almost instantly. When I applied it along a baffle seam from inside the cabinet it wicked all the way through the joint and was visible all along the outside of the seam.
I recommend super-thin CA for gluing the seams.
I don't think the front baffle was glued at all except for maybe at the wood blocks. The super-thin CA has a water-like consistency. Due to the tight joint fit it wicks into the wood and kicks off almost instantly. When I applied it along a baffle seam from inside the cabinet it wicked all the way through the joint and was visible all along the outside of the seam.
- All seams were sealed with super-thin CA glue.
- The cab was lined with mattress topper.
- The TF0818 was gasketed and installed. Before the swap I was getting farting from the stock driver. Now there is more bass and no farting noises.
- The cab was tuned to 55Hz with a port screwed in to the stock port. The port is 3.25 inch of sch40 PVC (2" ID) hot glued to a 1/4" plywood flange.
