Hiwatt DR103 Build Part 2: Schematic and Main Turret Board!

[@tone1798]

Congrats on the subs! Obviously I don’t know how far you want to take this channel? I hope more than you could expect! Why? Your detail, your technique and inspiration!!! I appreciate your respect for those who came before you and the builds! Great work Joe!

[@graybenchelec]

Thanks!

[@analogblues9606]

As someone mentioned, please give us a full cost build. I may consider making one. I’m a new subscriber and you’re doing an awesome job! Keep them coming! Thanks!

[@martinreid1740]

Nice attention to detail, looking forward to the next episode.

[@graybenchelec]

Thank you!

[@latergarside-244]

This is really cool man

[@graybenchelec]

Thanks!

[@ryvers]

cool video with nice soldering skills! Really excited to see how this amp will turn out

[@graybenchelec]

Thanks!

[@mrrootytooty5797]

As always, great job :)

[@graybenchelec]

Thanks :)

[@alexisdrosopoulos]

Great job as always! Don't know if you're already planning on doing it, but it would be really interesting to see a parts cost rundown in case someone is interested in building one as well. Also the bus wire on top looks neat af. It's one of those cases that practicality is more important than looks, but I'll say it looks damn good. Can't wait for the rest of the build. Take care man!

[@graybenchelec]

Not a bad idea, thanks!

[@eoinodunlaing4391]

Great stuff-I wonder if you noticed a difference when soldering components after wire brushing-I suspect the earlier wire soldering difficulty may have been due to terminal oxidation? Are you guys still using 60/40 lead solder?

[@graybenchelec]

Yeah I wire brush terminals and turrets to give clean metal, oxidized metal is hard to solder to. I use 63/37 solder.

[@Bushprowler]

Really enjoying this series so far! Keep up the good work.

[@graybenchelec]

Thanks, will do :)

[@petercornell2002]

Thanks Joe, dreat vid.

[@graybenchelec]

Thanks!

[@waynegram8907]

Why are you using the Drimel Tool wirewheel to strip off the nickel plating of the turret posts?

[@buzzedalldrink9131]

looks great where do you get resistors like the ones you used for the preamp/ phase inverter board? thanks

[@graybenchelec]

Those are 1W Dale CMF60 metal film resistors, I buy them from Mouser.

[@buzzedalldrink9131]

@@graybenchelec thank you! just subscribed! I want to build a hiwatt Still looking at all your videos great stuff!! You are a talented guy, thanks for the info!

[@anrque]

You were building a separate bias supply since your transformer doesn't have the extra winding like the original, so when you start on the power supply section it will differ from the traditional schematic and layout. However, I hope you can address a question I have about the original. I'm asking because I recently bought a clone kit from Mojo. The Mojo schematic, much like Mark Huss's like you displayed, show the transformer secondary connected to a resistor and then a diode to create the negative voltage needed for the bias. However, every layout and picture of a 100W Hiwatt has the diode off the transformer first and then the dropping resistor. I looked up the resistor-diode circuit and it seems like order doesn't matter in this instance. What's bugging me is that with the known high build quality for the original Dave reeves Hiwatt stuff. How or why would they have such a basic schematic/layout mismatch? Or am I just being an old man yelling at clouds?

[@anrque]

I have ver 2 and ver 3 of the Mojo schematic. It looks like they addressed this issue in ver 4 currently posted on their site and changed the schematic to keep the layout unchanged. I was just wondering about voltage hitting the diode before the resistor and whether there was any danger in that.

[@graybenchelec]

I've seen all kinds of different configurations. I've even seen bias supplies built off the primary of the PT. It's arguable the hiwatt supply should be modified anyway, to allow for adjustment of the bias voltage via potentiometer. The bias supply just needs to deliver the required negative voltage to the grids of the power tubes. Whatever combo or configuration of resistors/caps/diode makes it happen, should be fine.

[@simonlynch6080]

I’m hooked, like a Netflix series, waiting for the next instalment. What sort of fan are you using there ? Cheers

[@graybenchelec]

It's quite special to me, my niece bought it for me for Christmas. It's similar to this: www.amazon.com/Zuvas-Rotation-Portable-Personal-Electric/dp/B09T5GKF4Z/ref=sr_1_2?crid=2TZ4IERU3LG69&keywords=desk+fan+metal+USB&qid=1674416543&sprefix=desk+fan+metal+usb%2Caps%2C75&sr=8-2