Matchless HC30 clone mods?

[Ledvedder5150]

I'm hoping you guys can help me with some mods for my HC30 clone. I'd like to reduce some bass and flubbiness in both channels, as well as increase gain just a bit. I'd still like it to clean up when rolling back the guitar volume. The reason I'm looking for these changes is because I mainly play humbucker equipped guitars and closed back cabs.

Dizzy30Ceriatone.jpg

[Ledvedder5150]

Nik also shared a layout to make this more like an AC30, but it seems that these changes would make the bass even more flubby? Maybe I'm wrong about that?

AZ30-17July2016-V1.jpg

[Lynxtrap]

You could try lower values for the cathode bypass caps in the preamp.

[pdf64]

There’s some pretty severe high pass filtering available in both channels.
Maybe the issue is you just don’t get on with open loop power amps?

[Ledvedder5150]

There’s some pretty severe high pass filtering available in both channels.
Maybe the issue is you just don’t get on with open loop power amps?

Yeah, I'm almost wondering since I've been playing Marshall type amps for so long, that it'll just take a while to get used to this type of circuit. I'm trying to get tones similar to this video, but I just haven't found them yet.

https://youtu.be/tmXntEIrnKs

[Lynxtrap]

Yeah, I'm almost wondering since I've been playing Marshall type amps for so long, that it'll just take a while to get used to this type of circuit. I'm trying to get tones similar to this video, but I just haven't found them yet.
https://youtu.be/tmXntEIrnKs

I just watched the first couple of minutes where he plays the Epi. The bass is loose there too, he just plays stuff that doesn't make it stand out.

[LOUDthud]

Reduce the two caps from the PI to the Master Volume dual pot from 0.1uF to 0.047uF or 0.022uF.

On the VTB channel, reduce the cap from "F" to PI pin 7 from 0.047uF to 0.022uF or 0.010uF.

[Ledvedder5150]

Reduce the two caps from the PI to the Master Volume dual pot from 0.1uF to 0.047uF or 0.022uF.

On the VTB channel, reduce the cap from "F" to PI pin 7 from 0.047uF to 0.022uF or 0.010uF.

F to PI pin 7 is already 0.01uF.

The two cap from the PI to the MV were 0.047uf. I reduced them to 0.022uF. It seems to help a bit.

[LOUDthud]

F to PI pin 7 is already 0.01uF.

The two cap from the PI to the MV were 0.047uf. I reduced them to 0.022uF. It seems to help a bit.

OOPs ! I was looking at the wrong layout.

To up the gain on Ch-1 there are a couple of things you could do. Try one or both. There is a 10dB attenuator just before the Effects Loop. It is the 220K and 100K resistors to ground connected to point F. Remove the 100K (or change to 1Meg) and short across the 220K. This will increase the signal level in the Effects loop to the point most Effects will distort at the input. Not a problem if you're not using Effects. If you get what's sometimes called blocking distortion at the input to the PI, go back and change the 220K to 100K or experiment until the blocking goes away.

This next part will change the way the DC coupled cathode follower sounds. Change the 56K resistor to ground from V2 pin 8 to 100K. Change the 1.5K from V2 pin 3 to ground to 820 or 750. This will also increase the signal level in the Effects loop.

[Ledvedder5150]

To up the gain on Ch-1 there are a couple of things you could do. Try one or both. There is a 10dB attenuator just before the Effects Loop. It is the 220K and 100K resistors to ground connected to point F. Remove the 100K (or change to 1Meg) and short across the 220K. This will increase the signal level in the Effects loop to the point most Effects will distort at the input. Not a problem if you're not using Effects. If you get what's sometimes called blocking distortion at the input to the PI, go back and change the 220K to 100K or experiment until the blocking goes away.

Do you mean the 220k and 100k at point D?

[LOUDthud]

Do you mean the 220k and 100k at point D?

Yes.

[Ledvedder5150]

Do you mean the 220k and 100k at point D?

Yes.

Any suggestions for upping the gain a bit on the Ef86 channel?

[Ledvedder5150]

I changed the PI input caps to 0.0047uF. I'm still not feeling it. There's still this woofiness about it that just isn't vibing with me. Maybe it's my guitars or cabs? Even when I turn down the gain (volume) on either channel, as it cleans up, it seems bland to me. No chime or sparkle.

Here's what I've changed so far from the stock circuit -
1. PI input caps from 0.01uF to 0.0047uF.
2. PI output caps from 0.047uF to 0.022uF.
3. 1st channel bypass cap from 25uF to 1uF.

Tungsol 12ax7's
EHX EF86
JJ EL84's
JJ GZ34

[LOUDthud]

Any suggestions for upping the gain a bit on the Ef86 channel?

I have zero experience with the EF86, but from the Mullard Data sheet it looks possible to increase the gain by increasing the plate current. Need to plot some load lines. The tricky part is setting the screen Voltage.
Link: http://www.tubezone.net/pdf/ef86.pdf

I wouldn't feel comfortable recommending anything without prototyping it. I have a couple of Sovtek EF86 from probably 10 years ago.

I'm surprised you find the DC30 bland because it doesn't use feedback. What are you using for speaker(s) ? What do they sound good with ?

[Ledvedder5150]

Any suggestions for upping the gain a bit on the Ef86 channel?

I have zero experience with the EF86, but from the Mullard Data sheet it looks possible to increase the gain by increasing the plate current. Need to plot some load lines. The tricky part is setting the screen Voltage.
Link: http://www.tubezone.net/pdf/ef86.pdf

I wouldn't feel comfortable recommending anything without prototyping it. I have a couple of Sovtek EF86 from probably 10 years ago.

I'm surprised you find the DC30 bland because it doesn't use feedback. What are you using for speaker(s) ? What do they sound good with ?

I have a Suhr PT212 with greenback/V30, and a custom 212 with a v30/G12H-30.