Boosting the Blackstar HT 40 Drive Channel

funkadelic

Hi. Have anyone tried boosting the Blackstar HT 40 drive channel? Meaning a gain boost. I used a Boss Dual Overdrive (green channel, gain almost zero, volume almost maxed [Previous error fixed]) to boost the Blackstar drive channel set with the gain between 2-3. This was the result:
1. On the Classic Crunch voice the sound disappeared..came back..disappeared...etc. Don't know ho else to describe it except that the amp couldn't cope.
2. It faired much better on other Saturated Lead voice setting. It did what I wanted, i.e., added more gain.

I've always read about guitarists boosting their already overdriven amps and was excited to try this but what a disappoinment! Then I read that these amps are actually hybrid amps - solid-state preamp with a tube to help it out and a tube power section. Could that be the cause or do I have a dud amp?

Can anyone who has this amp (or any Blackstar HT venue amps) please shed some light on this?

Psean

funkadelic wrote: I used a Boss Dual Overdrive (green channel, gain almost max, volume almost zero)

Volume almost zero on the OD pedal? Usually to boost you push the pedal's volume and keep it's "gain" quite low.

AlanRatcliffe

Psean wrote: Usually to boost you push the pedal's volume and keep it's "gain" gain quite low.

+1.

"Gain" can mean one of two things (volume or drive) depending on how the amp is set up. If the amp is set up fairly clean, a volume boost will raise the volume, if the amp is set up so it's already distorting, the extra gain will just make it distort more.

Overdrive from a pedal doesn't necessarily push an amp harder, it just adds distortion to the signal that the amp then makes louder. That's usually the approach if you want gain at more controllable volumes with a non master volume amp.

I don't know the HTs, but some amps with solid-state front ends designed to be clean (getting their drive from later in the circuit) cannot take too much signal at the input without sounding nasty.

funkadelic

Sorry made a mistake. The Boss Dual Overdrive Volume = almost maxed and Gain = almost zero. Apologies for that.

AlanRatcliffe

OK. Sounds like you're hitting something in the amp too hard. Try back off volume on the pedal until it opens up.

psyx

Does the SS preamp section function on the clean channel as well? If not then you can drive the clean channel with a high gain pedal to give you the saturation you desire, without the nasty response.

Psean

Alan Ratcliffe wrote:
Psean wrote: Usually to boost you push the pedal's volume and keep it's "gain" gain quite low.
I don't know the HTs, but some amps with solid-state front ends designed to be clean (getting their drive from later in the circuit) cannot take too much signal at the input without sounding nasty.

I reckon that's the most likely source of the problem. Usually when you boost gain with an OD's volume pot or a boost pedal, it's to push the valves in the preamp further into overdrive. As Alan says, If you're doing that into a solid-state pre, it won't respond the same - i.e. usually not nicely. So even if the amp isn't a dud, maxing the OD's volume wouldn't be the best way to increase the gain you're getting out of the amp.

Psean

funkadelic wrote: Blackstar HT 40 ...
...Then I read that these amps are actually hybrid amps - solid-state preamp with a tube to help it out and a tube power section. Could that be the cause or do I have a dud amp?

Is this the amp? Or is there another HT40 (not "Club")
http://www.blackstaramps.com/products/ht-club40/

'Cause I see nothing about it having a solid-state pre-amp.

40 watt, 2xECC83, 2 x EL34

ECC83s would be the preamp valves...

funkadelic

Blackstar HT Club 40 yes. That's the one. Did quite a bit of reading on the Net, and it can get quite technical and way over my head. Basically what was stated is that the preamp uses op-amp circuitry to get the signal level up to a point where the ECC83 will overdrive. The ECC83 is at the end of the preamplifier signal path and adds the tone, compresseion, and overdrive. Each channel has one dedicated preamp valve - one for the clean channel and one for the drive channel. Thereafter it goes to a solid state phase inverter(?) and to the EL34 power tubes.

Some call the amp a hybrid amp...some don't care...personally I wouldn';t have cared if it wasn't for my experience with the amp. Had no such problems with the Ibanez TSA30. I could hit the preamp valves hard and still get sweet tone out of it....

Nicholas-L

Yes from what I found was that it uses a Solid state Phase Inverter. Haven't seen the circuitry yet, but it might be possible that the IC's are "overloading." I don't really think Blackstar amps were designed for the feeling tone player, it seems more geared towards the high gain metal head. Try backing the volume of the pedal just a bit and adding a bit more gain on the pedal? ???