Help with Blackstar HT Dual pedal

[rosscocean]

Hi everyone,

I've been playing with an HT Dual, it's a 2 channel valve overdrive. I really like the second channel but there's a couple of things that bug me about the first channel:

1. The EQ of the channel, it sounds like it has a spike in the high mids.

2. It doesn't like to be boosted. If I put a boost or fuzz before it channel 1 sounds like it can't handle it, whereas channel 2 sounds nice. Which seems odd, as the second channel has more gain.

I've had a look at the schematic and I can't see a difference in the two channels. This must just be me, it's the most complicated schematic I've ever tried to read.

Anyway, I'd like to know the differences in the two channels. If anyone could help me out I'd really appreciate it.

Here's the schematic http://music-electronics-forum.com/attachments/23817d1371194012-blackstar-ds-2-ht-dual.gif

Thanks,
Ross

[GibsonGM]

Can you re-up the schema?  Can't load it for some reason...

[bluebunny]

The link was posted as an FTP link (although the text shows an HTTP link).  This should work:

http://music-electronics-forum.com/attachments/23817d1371194012-blackstar-ds-2-ht-dual.gif

[Ice-9]

That schematic is only a small section of the pedal, I just see the input buffer, chl change and bypass bits and the circuit around the 12ax7, chl1+2 are not in that schematic as far as I can see.

[rosscocean]

Thanks for your replies.

I'm really struggling to find a full schematic for it.

[rosscocean]

I think I might have found the other parts of the schematic
Here's a link to a post with them.

https://forums.rgc.ro/topic/52898-schema-blackstar-ht-dual/

[rosscocean]

I'm guessing the part with all the diodes is channel 2?

[Ice-9]

It certainly is, the signal comes from connector 2 pin 9 from the buffer/switching diagram and enters in at connector 11 pin 9. The schematic is a little difficult to follow with the connectors and you really need to look at the diagram as a whole to follow it as it is drawn is sections with the wiring connectors going from one diagram sheet to the other. Once you are used to reading this type of drawing it will be easy for you to redraw the audio path that you want to work with.

[J0K3RX]

Here is a link... You may be able to look at some of the other blackstar preamps to get a better idea of the flow of things..
http://schems.com/bmampscom/blackstar/