[Dirk]

Thanks a lot for the feedback. I will have one of the techs check the layout again and make sure that we update the drawing.

Best regards, Dirk

[nunonaos]

Some notes from my build:
-one of the solder pads in the pcb touches one of the screws  in the chassis, i couldn't raise the pcb more so i placed a piece of rubber to isolate the pad from the scres (otherwise it would be grounded)
-the negative feedback is disengaged when you pull the master volume, so it should have write "pull to remove negative feedback". Anoother way os solving this is changing the wires in the switch so that when you pull the master volume the negative feedback is on and when in the standard position the negative feedback is off
-when the tonestack is activated there is A LOT of volume loss, maybe with a bigger resister for the mids control this wouldn't be so aparrent. for me, the amp becomes unusable with the tonestack activated. maybe using a 12ax7 in the V1 could increase the gain in the amp if you want to use it with the tonestack activated...
-i really liked the silicon wires included in the kit
-i still have to try the amp in full blast and with other guitars, but my impressions are very good so far, i really like the sound of the amp

[nunonaos]

Another picture

[nunonaos]

picture showing where the pcb touched the chassis screw

[Dirk]

picture showing where the pcb touched the chassis screw

Am I blind ? Could you mark it on the picture ?

Tone-Stack: Yes, there will be a loos of signal when the tonestack is active. This is known and I mentioned it in the description too. If this makes the amp useless or not is hard to tell, and everyone has to decide by himself.
We have add the tonestack because many customers requested such a tonestack, it was and is a common wish. There are lot of DIY building a 5E3 because they think that it sounds like a Blackface but of course it doesn't so we tried to add an option to get a more crispy sound. Feel free to play with the values of the tonestack it self also with different tubes. A 12AX7 will give more gain but this will effect the hole amp of course.

Best regards, Dirk

[nunonaos]

Am I blind ? Could you mark it on the picture ?

Tone-Stack: Yes, there will be a loos of signal when the tonestack is active. This is known and I mentioned it in the description too. If this makes the amp useless or not is hard to tell, and everyone has to decide by himself.
We have add the tonestack because many customers requested such a tonestack, it was and is a common wish. There are lot of DIY building a 5E3 because they think that it sounds like a Blackface but of course it doesn't so we tried to add an option to get a more crispy sound. Feel free to play with the values of the tonestack it self also with different tubes. A 12AX7 will give more gain but this will effect the hole amp of course.

Best regards, Dirk

i placed a green rubber between the screw and the pcb. you can see the green rubber between the bias and ac tap pads

regarding the tonestack. i think its a good ideia to include it. for me, personally, i think ill change the mids resistor but its a personal taste.

[456Onno456]

Hi,

regarding the loss caused by the activated blackface-TS: attached you will find a zip containing all spice files necessary to simulate exactly that part of the circuit (I use LTSpice). Without having build or played the amp, I find it reasonable that this implementation may be on the edge of 'unplayable' (see attached picture, red is the curve for a lifted TS). I am not aware of a blackface utilizing such a tonestack without a recovery stage before the PI (hence the signal may not be enough to drive the poweramp, in particular with the NFB activated).

My recommendations:

a) increase the 3k3 to at least 6k8.

b) use a 12AX7 in V1 position

c) implement a switch to increase the cathode bypass cap of V1 in blackface mode. Keep the additional cap between 2µ2 and 10µ. This will give you more of a blackface style response.


cheers,

Max

[nunonaos]

Hi,

regarding the loss caused by the activated blackface-TS: attached you will find a zip containing all spice files necessary to simulate exactly that part of the circuit (I use LTSpice). Without having build or played the amp, I find it reasonable that this implementation may be on the edge of 'unplayable' (see attached picture, red is the curve for a lifted TS). I am not aware of a blackface utilizing such a tonestack without a recovery stage before the PI (hence the signal may not be enough to drive the poweramp, in particular with the NFB activated).

My recommendations:

a) increase the 3k3 to at least 6k8.

b) use a 12AX7 in V1 position

c) implement a switch to increase the cathode bypass cap of V1 in blackface mode. Keep the additional cap between 2µ2 and 10µ. This will give you more of a blackface style response.


cheers,

Max

thank you for the input

i will change the resistor to 8K.
changing the preamp tube only makes sense if i only use the blackface "mode" so maybe i'll test it but i don't think i'll keep it because i like the standard sound of the amp
i think that i would need switch with 3 poles to switch caps when activating the tonestack so (at least for now) i won't try that mod

[nunonaos]

Hello

I ran the b+1 and b+2 wires close to the tubes sockets, on the side of the pcb,not under or above the pcb like the photos of the tube town build

Should I reroute this wires so thew stay farther away from the tube sockets?

[nunonaos]

Hello

I ran the b+1 and b+2 wires close to the tubes sockets, on the side of the pcb,not under or above the pcb like the photos of the tube town build

Should I reroute this wires so thew stay farther away from the tube sockets?

Can anyone help?

[Bluesboge]

Hi, I lay the cables in this place in the housing corner under the circuit board.

[nunonaos]

Hi, I lay the cables in this place in the housing corner under the circuit board.

thank you, my cables aren't exactly like that but they are in the same place. yesterday i tried moving them a bit and didn't noticed and improvement in hum so i guess this is as good as it gets.

the hum is not bad, it's a normal hum like in every amp, i was just investigating if i could reduce it

thanks

[Bluesboge]

A light latent hum, I also think, this is normal ....


greetings

[456Onno456]

Hi,

if you are still chasing hum in these amps then try connecting the ends of the two 100R resistors that are currently going to the star ground t o the cathode of the output tubes. It is sufficient to connect them to the cathode side of R23 on the board.

This results in a modest heater elevation (poor man's heater elevation, even Valco did it) when the amp is operated in cathode bias mode. You can easily compare the result by switching between the cathode and fixed bias mode, as in the fixed bias mode this elevation is rendered ineffective.

If this helps, a permanent heater elevation working in both modes is also not too hard to implement.

cheers,

max

[nunonaos]

Hi,

if you are still chasing hum in these amps then try connecting the ends of the two 100R resistors that are currently going to the star ground t o the cathode of the output tubes. It is sufficient to connect them to the cathode side of R23 on the board.

This results in a modest heater elevation (poor man's heater elevation, even Valco did it) when the amp is operated in cathode bias mode. You can easily compare the result by switching between the cathode and fixed bias mode, as in the fixed bias mode this elevation is rendered ineffective.

If this helps, a permanent heater elevation working in both modes is also not too hard to implement.

cheers,

max

I've never heard of that method, thanks

I have compared it to another amp and I think this has regular hum, not more, not less.
But I guess it doesn't hurt to try that method.

Thanks