This is NOT meant as a knock, but llke the sleeper aesthetics. Sort of like a space heater you could walk over to, plug in, and rip a big Am chord - and everyone's goin' "huh"?

Wes
SoCal ex-pat with a snow shovel

DISCLAIMER: The above is opinion/suggestion only & should not be used for mission planning/navigation, tweaking of instruments, beverage selection, or wardrobe choices.

wfoguy wrote:

I wasn't happy with what I had done earlier in the day so I removed it and started over. I was using Microsoft Publisher which I used for the first time today. I installed the TDA7297 board to power it up. I'm going to experiment with separate power supplies before combining all the inputs to 1 power supply. I have installed a terminal strip inside the case to facilitate connecting all components with ease for all the changes. When the Surfy Trem kit is available, it will be simple to connect into the series.

Wfoguy, please take care when you try to power all cicuits with one supply. The ground on the input of the amp is probably a 'virtual ground'. It allows a symetrical amp to be powered from an asymmetrical power supply. Because the Surfy Bear has a true ground it will cause your amp to short out.

Addendum: You can check the amp for a virtual ground if you trace the input ground on the PCB. If it physically connects to the power ground you can use a single power supply. If it's not directly connected to power ground it's probably a virtual ground.

Last edited: Feb 06, 2017 04:00:57

wfoguy wrote:

Frank, I was going to hook the power supply to my terminal strip. It will have + and - on one side and all the components hooked so the same polarity on the output side. Isn't this the same as a daisy chain power supply for pedals? None of the components are mounted to the same metal component except for the pots and jacks in the alum. top plate. Am I missing something about pcb's that I know very little about?

I know it seems a logical thing to do, but it can fry your amp in a second. It is quite hard to explain without being able to draw the diagrams. The fact is that the ground of the amps input isn't connected to the ground. To be precise it's at half the voltage your using to power it. To connect the Surfy Bear you have to connect the amp's input ground to the output ground of the SB, right? That's when you short half the power supply to ground and most of the time it's the end of the amp. So do the tracing like I described in my first post and find out if your amp is safe to daisy chain.

There's another problem these amps have: the groud or minus of the speaker connections can never be connected to the chassis or the ground of the power supply. Its caused by the same design feature, so if the documentation warns you not to connect the speakers to ground be careful NOT to daisy chain your amp.

This will be the last post on this unless I discover something very interesting. The bottom line is that if you use a pam amp, you can only use 1 channel of output so volume is limited. While that was the whole concept of this, you may find that it's too limiting. With the reverb bypassed, there is adequate volume but by running the signal through the reverb, the volume is cut substantially. Because of that, I will recommend you start with a TDA7297 amp. I paid $2.59 with shipping for the one I'm using. The pam 8610 is available for less than $3 also. I'm not going to mention the 3 or 6 watt version of the pam because you would have to use a smaller speaker to have much.
This is the list of components I used:
Surfy Bear kit, $62,
Accutronics 8AB3C1B, 6 skirted knobs, P-K314-1-A, total from Amplified parts, $41.41 with shipping
G8C 8" American Vintage speaker from Musician's Friend, $45.51 with shipping
S-H273X rca cable from Amplified parts to connect the tank to the fet-verb, $3.50 plus shipping
1/4" male to 3.5mm male stereo cable, such as a Parts Express|Part # 240-069, $2.70 plus shipping. I bought mine years ago and don't remember where I got it from. This example is way too long but it will allow you to see what is needed to connect from the fet-verb out to the amp in.
I'm using the 1 amp power supply for the vet-verb and a 3 amp laptop power supply for the amp.
I'm using a 12v. blue led for a power light but any 12v light would be sufficient. I have it connected to the power supply side of the amp so when it's plugged in, the light is on. All these amps I experimented
with have a led on them so if it was visible, you would have a power light.
The wood I used was left over from other projects and the top was made from alum. The legend for the controls was printed on a color laser with vinyl sticker material from Texascraft.com. It costs $1.87 a sheet plus shipping.
I hope this will answer questions about this concept. I didn't do this the cheapest way possible but you can see what was involved. If you have used components around, this could be very inexpensive to do.

Last edited: Feb 12, 2017 18:16:40