Tremolo TMB Questions

[JMPGuitars]

Josh thanks for getting me started with chassis and transformers. I'm sourcing all the parts and had a few questions. Are the 220pf in the treble circuit and .01uf caps in the tremolo circuit Wima style film caps? Can you recommend voltage and the lead spacing to fit the PCB. Link to Mouser or other would be great. Also what type of switches do i need for the reverb and tremolo circuits. One more, what type of tube sockets are best to use with the chassis. Remember, you said the need paitience is just beginning. Thanks

I know, I know.

There's a link to a Mouser BOM on the doc page: viewtopic.php?t=25550

Make sure you're using the PCB 1.4 docs.

I like Belton Micalex tube sockets.

Typical mini switches should be fine for rev/trem.

Thanks,
Josh

[Rvaughan68]

Thank you. It’s about to get real.

[Rvaughan68]

Josh is the 3.3uf 63V capacitor in the Mouser BOM in place of the 2uf cap fed from V2 P8?

[JMPGuitars]

Josh is the 3.3uf 63V capacitor in the Mouser BOM in place of the 2uf cap fed from V2 P8?

Yup. I'm surprised I didn't put a note about that in the schematic. Eh, maybe some day.

Either value is good. I did put a note in the regular BOM: "Higher value for more bass."

[Rvaughan68]

Thanks. Raining here today so started populating the board. Missing a few caps but close.

[JMPGuitars]

Thanks. Raining here today so started populating the board. Missing a few caps but close.

That escalated quickly!

Start a thread for your build. Keep us posted on your progress, and try to compete with my heater wiring:

jmpguitars-heater-wiring.png

[Rvaughan68]

Ok the transformer connections shown on the layout show two 3.18 leads from the transformer to the output tube pins. The heater wiring image shows the leads from the transformer to pins on what looks like a different config. What pins do I need to land on from the 0 and 6.3V pins from the transformer to the EL 84 pins #s and then the pins from the EL 84s to the AX7s. Probably a dumb question but I accept it as such and ask anyway. Thanks in advance for guidance.

[Bieworm]

Ok the transformer connections shown on the layout show two 3.18 leads from the transformer to the output tube pins. The heater wiring image shows the leads from the transformer to pins on what looks like a different config. What pins do I need to land on from the 0 and 6.3V pins from the transformer to the EL 84 pins #s and then the pins from the EL 84s to the AX7s. Probably a dumb question but I accept it as such and ask anyway. Thanks in advance for guidance.

On the photo you see 2 octal sockets for the power tubes. Josh was building a 36 watt.
You need to run the wires to pins 4 and 5 on the EL84. Then to 4+5 and 9 on the preamp tubes.

[JMPGuitars]

Ok the transformer connections shown on the layout show two 3.18 leads from the transformer to the output tube pins. The heater wiring image shows the leads from the transformer to pins on what looks like a different config. What pins do I need to land on from the 0 and 6.3V pins from the transformer to the EL 84 pins #s and then the pins from the EL 84s to the AX7s. Probably a dumb question but I accept it as such and ask anyway. Thanks in advance for guidance.

On the photo you see 2 octal sockets for the power tubes. Josh was building a 36 watt.
You need to run the wires to pins 4 and 5 on the EL84. Then to 4+5 and 9 on the preamp tubes.

There are documents for both 18W and 36W versions. If you're building an 18W, don't use the 36W documents.

[Rvaughan68]

Thanks

[Rvaughan68]

Happy Father's Day to those who are. To those who aren't, holler at the old man. Now for the question. Do the shields of the shielded wire get soldered to anything? If so, where?

[JMPGuitars]

Happy Father's Day to those who are. To those who aren't, holler at the old man. Now for the question. Do the shields of the shielded wire get soldered to anything? If so, where?

Yes. Only one end of the shielded wire gets connected (if both ends are connected, it's not a shield anymore). The plates of V1 have shield connectors on the PCB. The others you can connect strategically. Look at photos earlier in the thread, you might see some examples.

Happy Father's Day!

[Rvaughan68]

Thanks again. Here is a pic of my heater wiring. Not as good as Josh's but that bar is pretty high.

[JMPGuitars]

Thanks again. Here is a pic of my heater wiring. Not as good as Josh's but that bar is pretty high.

Nice! Better than a lot of what we see.

You should improve your mechanical connection technique before soldering more. Review the soldering thread in my signature.

[Rvaughan68]

Thanks, will do. I can't tell from the picture in the thread but it looks like the shielded wire from V1,P2 to the input jack has one end of the conductor soldered to V1,P2 and the other soldered to tip of the input jack at the 1M resistor. Is the shield soldered to one of the legs that are jumpered together.

[JMPGuitars]

Thanks, will do. I can't tell from the picture in the thread but it looks like the shielded wire from V1,P2 to the input jack has one end of the conductor soldered to V1,P2 and the other soldered to tip of the input jack at the 1M resistor. Is the shield soldered to one of the legs that are jumpered together.

The shielded input wire is connected to the TIP of the input jack, and to the terminal strip that connects to the grid stopper resistor connected to pin 2 of V1. The shield wire needs to have a single and permanent connection to ground. You can do that at the input jack ground lug (that doesn't get lifted) or at the terminal strip ground lug where the screw mounts.

Review some of the photos in this post / thread: viewtopic.php?p=252120#p252120

The photo of the input jack wiring doesn't clearly show the tip wire, but rest assured, it's connected to the tip.

Thanks,
Josh

[Rvaughan68]

That’s great. Thanks

[Rvaughan68]

Finally getting around to ordering a combo cabinet from Mojotone. Ordering the front mount 18-watt British option, 10" deep to accommodate Josh's chassis. On the quote, Andrew listed
Shell Material: 1/2" birch, Finished Dims: (H) 20" x (W) 24" x (D) 10"
Finished Chassis Opening: 16-1/2" X 2 3/8. Josh does this look correct for your chassis?

[JMPGuitars]

Finally getting around to ordering a combo cabinet from Mojotone. Ordering the front mount 18-watt British option, 10" deep to accommodate Josh's chassis. On the quote, Andrew listed
Shell Material: 1/2" birch, Finished Dims: (H) 20" x (W) 24" x (D) 10"
Finished Chassis Opening: 16-1/2" X 2 3/8. Josh does this look correct for your chassis?

The only change from their standard dimensions for the British amp cabs is the 10" depth. You should be fine. If not, complain!

[Rvaughan68]

Great. Thanks