HT-100 problem...

[MetalPete]

Hi!
I've bought the HT-100 in early june this year and so far i really love the way it sounds. But recently I've discovered something that can be described as a "flaw".
The problem is about switching between channels. Straight to the point. When I want to switch from clean w/ voice on, straigh to OD2 w/ voice on. The problem is that the amp somehow loses it's power, and the sound is "inefective" to say it lightly. It's like the column (4x12) is standing in another room packed into a box it arrived in. The sound is weak just like it lost all it's "loudness" as if the volume knob went all the way down...
I don't know what to do, theoretically I still have my warranty, but i don't know will it help me in any case. Because from what i know Blackstar doesn't have a direct dealer in my country. I've checked and there's only one for two countries (Germany/Poland). Help?

P.s
The problem doesn't occur when i switch channels in order Clean>OD1>OD2 with or without the voicing, but it saddens me that I paid for this great amp and that i have this flaw, and from what I know I'm not the only one.

[eleloy]

The same here.
I'm from spain and i bought the amp at Thomann (germany)

I'd need an easy procedure for updating firmware for myself, however the blackstar support says "Unfortunately there isn’t another way round this as all internal operations should be carried out by a Blackstar technician and returning the amp to the point of purchase is how the amps are returned to our technicians. If any internal operations are carried out by yourself or another technician then your warranty would be void. Apologies for any inconvenience."

"The inconvenience" is two months without amp (I think)....

[Guitarzan]

I emailed Blackstar yesterday with the same problem and got the same answer as yourself. I dont even CARE about the warranty, I just want to be told how to fix it without having to wait forever to get it back. Don't they know some of us have gigs??

[eleloy]

Yesterday the sound diference was insignificant!!! Why??? I'm confused!!!!

[eleloy]

I really think that HT-100 is very inestable.
Switching is unpredictable. Now the issue is with clean voice off!!!
Working with "clean voice on" the OD2 works fine ... but it sounds different with "clean voice off"!!!!!

[Ellis Marauder]

I had the same issue with my HT-100. After quite a bit of searching and nagging, I got in touch with Blackstar's North American rep. He informed me that this problem was due to the amp's firmware. Basically, there is a chip on the circuit board that needs updating (swapping out). He was nice enough to find a local repair shop and then FedEx'd the chip to the repair shop. Once the repair shop received the chip, I was contacted and made an appointment to take my amp in. The repair was done in LITERALLY 15 minutes, in front of my face, and all of this was done at no cost to me. I took the amp home and put it through it's paces, (switched through all channels, voice switches on and off, ran effects through the loop, used the footswitch), and the amp performed flawlessly. No loss or degradation of sound at all switching from CLEAN to OD2.

My suggestion is that you contact Blackstar and ask for the same service. This is a manufacturing defect that is easily fixed.

[pacAir]

Thanks for the story and solution! I just bought a shipping damaged HT-100 I need to repair so I will look for this problem while I'm in there.

Since the HT-60 Stage combo shares the same basic chassis and feature set (and Owner's Manual) as the HT-100 I assume that this problem also exists with that model.

Here is a photo of the PIC processor inside my HT-40 Club that contains the firmware that controls the switching functions:





Notice how it is mounted in a socket. I would hope all the Blackstar amps are similarly built as this makes changing the chip a 15 minute job start to finish (most of the work is taking the chassis out of the cabinet and replacing it when finished).

The chip itself can be changed in under 30 seconds once you have access to it!


Steve

[Ellis Marauder]

That is precisely the chip. The tech used a pair of microchip tweezers to remove it and then just popped the new one in it's place. Not sure if there's a specific direction to place it. Make sure to confirm that to avoid any further issues.

Hope it works out for you!

[pacAir]

Look at the left side of the chip in the photo for the half-circle embossed in the plastic. This indicates which end of the chip has pin one (the pin at the bottom with the marker at the left side). You will probably damage the chip if it is plugged in backwards! It MUST be plugged into the socket in the correct orientation.

Well I checked the inside of my broken HT-100 this evening. At first I got the amp working (sort of) long enough to confirm that my amp doesn't suffer from the stated problem as far as I can tell (OD2 looks the same no matter where it come from on the front panel). I haven't tried it with the footswitch yet.

The chip in my unit is labeled as v2.0 so it appears it may already have the newer chip. The REAL problem I have is that the Bias supply has failed in such a way that it is a POSITIVE voltage! It should be -50vdc or so and it is currently +25Vdc! Output tubes go to RED PLATE as soon as power is applied, even if in standby!

The preamp, switching and high-voltage all work perfectly.

Does anyone know where I can get a copy of the schematic? I could fix this thing in 15-20 minutes if I had a clue about where the problem is located! I am kind of fishing in the dark checking transistors and regulators but haven't figured it out yet. This unit is not under warranty so taking it a shop makes no sense when I do all my own repairs (and have for 30 years).

Steve

[KKND]

@Steve:

http://www.musicradar.com/forum/showthread.php?t=66691

Hope this helps.

@Everyone else:

Please come to the HT Venue sub forum, i have been having serious tonal issues with my HT Stage 60 and i need suggestions, too many threads to link that's why please visit the sub forum.

Thanks