Blackstar Dept 10 Valve Pedals

[elfwash]

After surfing and lurking and googling, and not being a guitar player, and not
Really needing another interface, I found a couple of HT Dist pedals online
at half price. 125 for the pair.
One is new and one is used, but supposedly 'excelent condition', and 14 day returnable.
There are a few more new HT's to clear as well. A Drive pair for example. silly cheap.
All I really wanted was a driven valve output channel for the synths and VST's.
I almost wanted 2 Coopersonic Deluxe's but that's 4 times what I paid, so
silly really.
As I don't really need all that drive I may well swap the tubes for 12at's or
less even, see how it goes, I doubt they will be a stereo pair out the boxes,
one new and one burnt in.
Thanks for all the advice.

[ef37a]

After surfing and lurking and googling, and not being a guitar player, and not
Really needing another interface, I found a couple of HT Dist pedals online
at half price. 125 for the pair.
One is new and one is used, but supposedly 'excelent condition', and 14 day returnable.
There are a few more new HT's to clear as well. A Drive pair for example. silly cheap.
All I really wanted was a driven valve output channel for the synths and VST's.
I almost wanted 2 Coopersonic Deluxe's but that's 4 times what I paid, so
silly really.
As I don't really need all that drive I may well swap the tubes for 12at's or
less even, see how it goes, I doubt they will be a stereo pair out the boxes,
one new and one burnt in.
Thanks for all the advice.

No! Do not put a different triode in those pedals. The 12AX7/ECC83 pulls the least anode current when biased correctly. The 81/AT7 pulls more and the 82.AU7 even more current. The anode loads in the pedals are necessarily wee, 0.25W iirc, and you might burn them out.

In 'mainstream' valve gear these days such 'circuit bending' is usually harmless but it always pays to check. Some of the early Fender I seem to recall had 'just' high enough rated anode loads and peeps used to bugger 'em!

BTW if you have a valve amp with a front end 83 that is a bit noisier or hummier than you would like you can swap it for one in an HT. The valves are DC heated, no hum, and run at a high enough signal level that a bit of hiss is not noticed.

And! Don't swear and struggle to refit that spring clip on the valve. It was only really there for container shipping and the bottle will not shake loose by fair means without it!

Dave.

[elfwash]

Thanks very much for the advice.
I guess I'll use the AX7's then.
Turns out the new one has a 22V DC supply and the used one has a 16 VAC,
so checking on the scope, they look very different.
I doubt it is because one is new and one burnt in.
I think they may have tweeked the EQ blocks, because it's not possible
to match them at any setting.
Running one into the other sounds great though, so keepers at this price.
No problems driving them, nice input sensitivity actually.
Tempting to rack them up, with a long tail pair and a bunch of diode
configurations on switches for the ultimate mix and match overdrive.

[ef37a]

Thanks very much for the advice.
I guess I'll use the AX7's then.
Turns out the new one has a 22V DC supply and the used one has a 16 VAC,
so checking on the scope, they look very different.
I doubt it is because one is new and one burnt in.
I think they may have tweeked the EQ blocks, because it's not possible
to match them at any setting.
Running one into the other sounds great though, so keepers at this price.
No problems driving them, nice input sensitivity actually.
Tempting to rack them up, with a long tail pair and a bunch of diode
configurations on switches for the ultimate mix and match overdrive.

Checking what on the 'scope? Yes, early ones had an AC supply, no longer can be sold in EU. Don't mix them up. On something atmo will chat later.

Dave.

[elfwash]

In order to see if they would work as a matched stereo pair, I ran a sine
wave into them and found that the waveshapes were surprisingly
different.
The ISF EQ controls modified the waveshape in different ways as if they
had changed the filter configurations from old to new model.
Of course, backing right off on the input level gave me back the sine waves,
although on the new one, the higher frequencies were much more driven
than on the old one.
The old one also had a weaker low frequency response.
I didn't do any serious frequency analysing,but it was obvious the design
had been 'updated'.
Actually, in series, they compliment each other.

[Arpangel]

I don't want to mislead you Tony, the "compression" is quite a crude affair as its function is to prevent the first valve being driven too hard. Therefore it will only come into play at very high levels and will not behave anything like a Fairchild!

You see if valves are driven very hard you can get 'blocking distortion' which is not at all nice. N.B. You will not overdrive and damage the pedal with a synth level input and I doubt even +26dBu from a good mixer would harm it either.

Dave.

I would be using synths, hoping for a good valve overdrive, type sound.

[ef37a]

I don't want to mislead you Tony, the "compression" is quite a crude affair as its function is to prevent the first valve being driven too hard. Therefore it will only come into play at very high levels and will not behave anything like a Fairchild!

You see if valves are driven very hard you can get 'blocking distortion' which is not at all nice. N.B. You will not overdrive and damage the pedal with a synth level input and I doubt even +26dBu from a good mixer would harm it either.

Dave.

I would be using synths, hoping for a good valve overdrive, type sound.

Oh aye, they will do that. The response is of course aimed at guitars and guitar speakers, i.e. low bass and low treble beyond about 8kHz but there is a decent range of T&B boost available. All but the simplest pedal has speaker emulated output and should give nice results for recording.

Dave.

[Arpangel]

I don't want to mislead you Tony, the "compression" is quite a crude affair as its function is to prevent the first valve being driven too hard. Therefore it will only come into play at very high levels and will not behave anything like a Fairchild!

You see if valves are driven very hard you can get 'blocking distortion' which is not at all nice. N.B. You will not overdrive and damage the pedal with a synth level input and I doubt even +26dBu from a good mixer would harm it either.

Dave.

I would be using synths, hoping for a good valve overdrive, type sound.

Oh aye, they will do that. The response is of course aimed at guitars and guitar speakers, i.e. low bass and low treble beyond about 8kHz but there is a decent range of T&B boost available. All but the simplest pedal has speaker emulated output and should give nice results for recording.

Dave.

Thanks Dave, sounds like it’ll be OK, I’ll get one on sale or return.
I’m always a bit reluctant to fork out for distortion, as I can get it in more than one link in my recording chain, just by turning up the gain!

[ef37a]

I don't want to mislead you Tony, the "compression" is quite a crude affair as its function is to prevent the first valve being driven too hard. Therefore it will only come into play at very high levels and will not behave anything like a Fairchild!

You see if valves are driven very hard you can get 'blocking distortion' which is not at all nice. N.B. You will not overdrive and damage the pedal with a synth level input and I doubt even +26dBu from a good mixer would harm it either.

Dave.

I would be using synths, hoping for a good valve overdrive, type sound.

Oh aye, they will do that. The response is of course aimed at guitars and guitar speakers, i.e. low bass and low treble beyond about 8kHz but there is a decent range of T&B boost available. All but the simplest pedal has speaker emulated output and should give nice results for recording.

Dave.

Thanks Dave, sounds like it’ll be OK, I’ll get one on sale or return.
I’m always a bit reluctant to fork out for distortion, as I can get it in more than one link in my recording chain, just by turning up the gain!

Ah yes but it ain't THERMIONIC distortion!

Dave.

[Arpangel]

I don't want to mislead you Tony, the "compression" is quite a crude affair as its function is to prevent the first valve being driven too hard. Therefore it will only come into play at very high levels and will not behave anything like a Fairchild!

You see if valves are driven very hard you can get 'blocking distortion' which is not at all nice. N.B. You will not overdrive and damage the pedal with a synth level input and I doubt even +26dBu from a good mixer would harm it either.

Dave.

I would be using synths, hoping for a good valve overdrive, type sound.

Oh aye, they will do that. The response is of course aimed at guitars and guitar speakers, i.e. low bass and low treble beyond about 8kHz but there is a decent range of T&B boost available. All but the simplest pedal has speaker emulated output and should give nice results for recording.

Dave.

Thanks Dave, sounds like it’ll be OK, I’ll get one on sale or return.
I’m always a bit reluctant to fork out for distortion, as I can get it in more than one link in my recording chain, just by turning up the gain!

Ah yes but it ain't THERMIONIC distortion!

Dave.

Thermionic? even I wouldn’t pay three grand for distortion.

[Sam Spoons]

It's good to see this debate hotting up

Is that my coat?

[Wonks]

It's almost like an ode to valves.