Wiz MTL build with Burger PCB

[fusedbrain]

Use the DC elevated heaters feature of the board, your amp will be dead quiet.

Yes, the heaters will now be AC, but DC elevated

 

[fusedbrain]

In the OP you mentioned voltages in the context of an MTL. What plate voltage are you shooting for with an MCII and does it change for 50W vs 100W? 500vdc or just north of it is about as high as I comfortably go and I'm considering doing a 100W MCII.

I'm targeting 470v-480v max. I'll adjust the first droppers to hit the target voltage at the PI node, and the rest will scale out from there.
The 2 Wizards I owned ( still have the MCII ) were 510v +.
Not sure why Rick runs them so high, but it limits the options for EL34 reliability. JJ's seem to work, as do =C='s, and I've also used TubeStore Preferred series EL34's in high plate voltage amps, but that's about it.
I want to be able to use EH and Svetlana EL34's and EH 6CA7's in these builds. I briefly tried Svets in my MCII, just to check the tone, and they were glorious in that amp. Just no way I was going to run them long term at those voltages.

Burger's boards are really nice and recommended if you want to do a MCII build. Just be aware that shipping will take some time. Not his fault in any way, just the way things are in Oz with the Gov't and Covid etc.
I just received an order of loop boards from him that were shipped in April. They ended up coming into North America by boat, as it seems outbound flights from Oz are limited.
Next time I order from him, I'll discuss with him about using DHL or some other carrier besides the gov't post.
The boards are of such quality that they would still represent good value even with higher shipping costs

 

[hopkinWFG]

Just curious to know.. wouldnt a higher plate voltage make the amp sound wider more open?

 

[CornNutz]

In the OP you mentioned voltages in the context of an MTL. What plate voltage are you shooting for with an MCII and does it change for 50W vs 100W? 500vdc or just north of it is about as high as I comfortably go and I'm considering doing a 100W MCII.

I'm targeting 470v-480v max. I'll adjust the first droppers to hit the target voltage at the PI node, and the rest will scale out from there.
The 2 Wizards I owned ( still have the MCII ) were 510v +.

Last two wizzards I checked myself (a 100w MCII, and 100w MTL) both had 480vdc on the plates. Im guessing he went lower voltage these days. Make sense, since modern tubes cant really handle the voltage.

I have the Wizzard MC board from burger. Have it partially stuffed, but finding time for builds ATM is hard for me.

 

[SpiderWars]

I was looking at this one from MM:

MP100-475M-U

Marshall | 100 Watt | Power Transformer
Plexi — 475V B+ — with additional 12V @ 1A winding — Universal Voltage Primary

I don't know if or how much the extra preamp tubes will lower that B+. I think from there they jump to ~510vdc B+ at MM. If the extra tubes do bring it down I might use that.

 

[fusedbrain]

In the OP you mentioned voltages in the context of an MTL. What plate voltage are you shooting for with an MCII and does it change for 50W vs 100W? 500vdc or just north of it is about as high as I comfortably go and I'm considering doing a 100W MCII.

I'm targeting 470v-480v max. I'll adjust the first droppers to hit the target voltage at the PI node, and the rest will scale out from there.
The 2 Wizards I owned ( still have the MCII ) were 510v +.

Last two wizzards I checked myself (a 100w MCII, and 100w MTL) both had 480vdc on the plates. Im guessing he went lower voltage these days. Make sense, since modern tubes cant really handle the voltage.

I have the Wizzard MC board from burger. Have it partially stuffed, but finding time for builds ATM is hard for me.

The MTL I had was a 2012. My MCII is a 2016.

 

[fusedbrain]

I was looking at this one from MM:

MP100-475M-U

Marshall | 100 Watt | Power Transformer
Plexi — 475V B+ — with additional 12V @ 1A winding — Universal Voltage Primary

I don't know if or how much the extra preamp tubes will lower that B+. I think from there they jump to ~510vdc B+ at MM. If the extra tubes do bring it down I might use that.

MP100-475M-U - $280.00
http://www.classictone.net/40-18069.html - $151.19

Also, I remember CNutz mentioning that Heyboer had a PT similar to the Classictone model at a reasonable price, but I can't remember the details.

 

[SpiderWars]

Yeah, I know they are expensive. And more expensive doesn't mean better. But for me Heyboer is a no. I've had too many that had audible vibration (I am a stickler for this...perhaps too much) and swapping it for a MM has fixed it everytime. So I tend to go with what I know and justify $130 by prorating it and having a little more peace of mind. For the OT I wouldn't be as inclined to stick with MM but again, based on my experience with Heyboer tonally, that's still a no. I've never tried Classic Tone.

 

[CornNutz]

This is the custom power transformer that I had Heyboer build.

It is a modification of the Metro-Spec 100W PT Drake 1203-80-MS

This modification adds a 1amp 15v AC tap for switching and DC heaters. This will be perfect for BE clones, and other modded marshall style amps that need switching/dc heaters.

Part number is HTS-8205-MS15
Contact Arlyn Arendsen arlyn@heyboertransformers.net if you would like to purchase. I was paying $175 plus shipping. Not sure if the pricing has changed.

 

[fusedbrain]

This is the custom power transformer that I had Heyboer build.

It is a modification of the Metro-Spec 100W PT Drake 1203-80-MS

This modification adds a 1amp 15v AC tap for switching and DC heaters. This will be perfect for BE clones, and other modded marshall style amps that need switching/dc heaters.

Part number is HTS-8205-MS15
Contact Arlyn Arendsen arlyn@heyboertransformers.net if you would like to purchase. I was paying $175 plus shipping. Not sure if the pricing has changed.

Thanks for posting this
I'd like to try one of these.

 

[fusedbrain]

Yeah, I know they are expensive. And more expensive doesn't mean better. But for me Heyboer is a no. I've had too many that had audible vibration (I am a stickler for this...perhaps too much) and swapping it for a MM has fixed it everytime. So I tend to go with what I know and justify $130 by prorating it and having a little more peace of mind. For the OT I wouldn't be as inclined to stick with MM but again, based on my experience with Heyboer tonally, that's still a no. I've never tried Classic Tone.

OK cool
I never paid too much attention to PT hum or buzz, cause I cant hear it when I'm rockin out
I will say that the Metro-Heyboer C1999 Dagnal clone is the best sounding 100watt OPT I've tried.

 

[fusedbrain]

Finally, some progress

It's a Valvestorm project chassis, which is geared for 100watt builds, so I had to make some "adjustments"

The power transformer is a 50watt Classictone with a 5v / 3A tap for the relays. The choke is a Hammond 6H I had lying around, and the OPT is a Hammond 50watt project OPT they make for EL34 based amps. The primary impedance is a little higher than a Marshall style @ 3800 ohms, and it has a little wider bandwidth than the typical Marshall style OPT.
Should all be perfect for bringing the Wizard chug

Next step is wiring up the 12ax7 sockets and the pots to the PCB, and I still need to build the loop board.

I haven't ordered the face plates yet because I'm not sure of the final placement for all the pots and switches, or the labelling. For example, the "Rhythm Boost" switch might get labelled "Clean / Crunch", cause that's kinda what it does.
I not going to use any push - pull pots either, so all the function switching will be mini-toggles, with some of the functions made foot-switchable.
I can do up to 4 f/sw functions using a 5 pin DIN connector, and I can make my own foot switch from a small Hammond enclosure, but it could end up as simple as a 2 button f/sw for channel and Lead boost. I need to get the amp running first and see what I need.

There will probably not be any front panel LED's either. If I need indicators for status, I'll put them on the foot switch, where I'll see 'em
I'm not a fan of the pull pots and all the LED's on the front panel of my MCII.

Really looking forward to finishing this and firing it up.
More soon I hope

edit: I cleaned up the OPT and speaker ground wiring a bit and up-loaded a new pic.
Note that all those loose ends bent up at 90 degrees terminate in the PCB.

 

[SpiderWars]

Looks clean and pro. I was just inside my 2xKT88 UL amp that I put a simplified MCII preamp into (only 3x 12AX7 including PI) this weekend. It sounds so much better loud...my ears are ringing.

 

[glpg80]

Great attention to detail! Build looks like it’s coming right along!

I did the same thing and added LED status to the footswitch and not the amplifier. Just seems cleaner and more functional.

 

[SpiderWars]

I have had good experience with Heyboer ,my first real build used an OT from a company called Obsolete Electronics and I'm almost certain it was wound by Heyboer and it sounds great. That amp has been rebuilt and re-PT'd like 3x and is now the Jose in my sig but that OT has remained throughout. It was my Rocket and other Trainwreck-ish amps that turned me.

 

[glpg80]

Im a big fan of Marstran, Heyboer, or Merren. If doing repairs for others I’m not against using classictone to save some coin at customer’s request.

 

[burger]

Just completed another MTL, this one in 100w guise.

 

[fusedbrain]

Just completed another MTL, this one in 100w guise.

That sounds really good
If my build sounds anything like that, I'll be quite pleased, to say the least.
Just curious about the rhythm channel of the amp in the vid. It sounds great, but you mentioned something in the video about changing one or 2 things.
Does the MTL layout in the current build docs reflect these changes vs a stock MTL, or is the amp in the vid slightly tweaked from what is shown in the build docs?
I'd really like my rhythm channel to sound like the amp in the vid, ( I hated the rhythm channel on the 2012 MTL I owned ) so if there are a couple of tweaks not shown in the build docs, can we get the details?
I haven't started connecting my PCB to the rest of the amp yet, so now would be a great time for me to make adjustment, if required.
Thanks

 

[burger]

Hey man, thanks.

I think the 'couple of changes' are simply:
- Change R82 on my schematic from 220k to 470k, this will dump less signal to ground
- Install a global master so you can crank the rhythm channel volume

If you want more gain still, change R5 in my schematic from 4k7 to 10k. Just bear in mind that this effects the lead channel too!

 

[fusedbrain]

Hey man, thanks.

I think the 'couple of changes' are simply:
- Change R82 on my schematic from 220k to 470k, this will dump less signal to ground
- Install a global master so you can crank the rhythm channel volume

If you want more gain still, change R5 in my schematic from 4k7 to 10k. Just bear in mind that this effects the lead channel too!

Thanks for sharing