Chienmortbb

If its really cheap I might put a class d amp in it lol. If its the one at £199 it looks a little dear to me.

I love dowels.

Screw it then take the screws out when glue is dry and dowel the holes?

Too many demands on my time at the moment but I have made progress. I Finished wiring the amp, including re-installing the original board and converting it to BTL. It is all working I’ve played through for a couple of hours through a PA cab. It sounds good but I am biased. I’ve decided to put a switch in where the DEP Switch was. The original preamp design had a bright switch and I have decided to incorporate this. You can see the red switch between two of the pots on the photo below. Other things to do are to add the auxiliary input. You can see the upturned white capacitor wire-tied to the red one, that will form the auxiliary input in place of the effects return. I am not using effects send and return on this build. To use an auxiliary input requires the front panel to be drilled and there is space next to the instrument input. I am also considering whether to install an dedicated headphone out rather than bridging the DI out( currently labelled Headphone. more later.

Why do you want to do it? You may find that the pickups are not ideal for "passifying" and it might cost you close to £200 in the end to get where you want to get to.

Protection from Pesky Englishmen?

The switch arrived and of course I originally installed it the wrong way round. After 20 minutes I managed to get it out and change it around. The original switch was stuck with silicon to ensure it did not move, I don't have any of that so used some UHU. I will update when the UHU is dry. I also decided to take the balanced Headphone/DI output from the output of the pre-amp, before the master volume rather than the EFX Send. This is so is is after the EFX return/aux input.

Plus After 80. 8" 100W combo built in an Ashdown After Eight chassis and cab.

You can add the After Eighty to my list if I can stop blowing it up.

Made me chuckle,

I think you are right and I believe the thumpinator is lower than 30Hz although I have never measured one and they do not publish a spec.

I got the fuses and.......they blew but protected the 50ASX2 module. I replaced the fuses with 115R 1/4Watt resistors. These would eventually burn out if there is a problem but hold up long enmough for some faultfinding to take place. Th +ve resistor was burning out, cleary there was a short somewhere. After almost a day looking for the problem I found a small whisker across two tracks on the positive regulator side. Cleared it an all is good. Then I connected everything up gradually, the preamp worked fine but as soon as I connected the unbalanced/balanced/bridge converter the fuses blew again. Disconnected the UBB board and switched on, all OK. Switched off and the mains switch went a bit wobbly. So I have ordered a new one but that will be here midweek.

This is of course true.

Why downplay it Frank?

You must have read my mind. I took out the two through hole, PCB fuses and checked the voltage upstream of the fuses. Both were around 26.5V suggesting that the fuses had protected the module. I decided to bypass the on board fuses and fuse at F315mA. The onboard fuses are, as you say T400mA so there is some safety margin. As you probaby know, the F indicates quick blow and the T before indicate slow blow or time delayed. In this case the F315mA should blow well before a T400mA, protecting the module.even with the fan, the current draw from either supply should be under 150mA, so I should be OK. Sadly the next day delivery I paid for has failed so I will have to wait until tomorrow to proceed unless I risk another module...... can he wait?

Oh dear. It had to happen. Things were going far too well. I had been assmbling checking and then testing as I go. The pre-amp wiring and testing went well, apart from the crossed wires on the gain/volume. Sadly I had problems getting the opamps into the sockets in the unbalanced to balanced converter board. The pins got bent a couple of times. but eventually I got them in. In my hurry to get things moving, I did not notice that one of the chips was in backwards. The result was that I blew the auxilliary supplies. My own fault. I should have fused the power supply board. I will investigate the problem but luckily I have three modules and so I can carry on. I have modified the power supply to include fuses and have ordered some fuses. These should arrive tomorrow and I will carry on then.

I believe that there is a warehouse with lots of flour, eggs and GAS tokens somewhere near Heathrow.

Nice touch. I love Ashdown.

I tend to agree. The switching contacts on jacks are not too reliable, it would be better to have a separate switch but as it is designed in, the contacts need to be cleaned from inside the amp if needed.

Here is a picture from another angle, I have highlighted where the next wires will go. The one from the preamp output (purple) is so short, there is no point in using screened cable. For the one that goes from the EFX send to the faux DI out (turqoise/light blue), I may use a screened cable. This design was designed to use high quality audio opamps but for the purpose of testing I have used TL-082,TL072 and NE5532. Once I have finished testing I will use OPA2034 and either LM4562 or one of the high quality Linear/Analog Devices bipolar opamps.

Well I have put power and signals through the preamp and s seems to be working well. I did encounter one problem. No signal after the volume/gain control. Turns out I wired it in reverse. All the pots were wired with the same coloured wires. Brown, Red and Yellow. I am not at home at the moment so don’t have access to all my bits and pieces. On the preamp PCB, the pot connections are labelled 1,2 & 3. So bass pot connections are b1,b2,b3. The resistor colour code has Brown=1, Red=2, Orange=3 Yellow =4. As I have no orange wire, I used yellow. So whenI looked under the board, I could easily see that wires 1 & 3(4) were reversed on the first volume pot. So I changed those over et voila. Signal all the way. @Passinwind designed the PCB to be double sided so there were pads on both sides to solder the wires to. I xchose to solder from below to make it look better. Had I wired it with all the wires on top, I might have seen my mistake sooner but it would have looked like a rats nest.

Careful, you will have me putting the 125ASX2 amp in instead. My idea for this was a practice amp that could be taken to open mic night.I have PA support there so this could be enough on its own for that. I will save the 125ASX2 for the active 1x12 when lockdown ends.

Some progress.The four pots that are connected to the pre-amp PCB have been wired as can be seen in the picture. I have also been having some thoughts on the hole left by the DEEP switch and the unused Effects Send and Return features of the preamp. I will use the effects send to be the input to one side of the balanced transmitter, the side that feeds the line out (formerly the headphone output). The effects return will be repurposed as the Aux input for practice, after all this is a practice amp. So the next question is, use the Deep hole for the Aux input or drill a new one somewhere else? That can wait. I now only have to connect the +/-15V rails to start testing. It makes sense to test one part at a time so I will check the preamp is working before connecting the to the Unballanced to Balanced converter board. Of course I also still have to convert the module to Bridge Mode (BTL) but more on that later.

Yes I came to the conclusion that the Ghent cables are cost effective and well made, so there is no sense trying to make your own. It was never a job I enjoyed in the past even having the correct crimp tool. I realise I have slipped a bit behind but hope to make more progress today. The Garden Funiture however is finished. I might use that finish on a bass soon.