blackstar HT-1R QC problems.

[tonequester]

Tonequester here. This is my first forum experiemce, so please pardon, and feel free to advise me on anything that I would do that is not proper to convention.
Heck, i don't even know if this is the right forum on this site for what I have to say, but I'm going to give it a try in the hope that it might help someone avoid a
problem. I purchased a Blackstar HT-1R close to a year ago now. iwas wanting a small All Tube amp. I let the salesman steer me to the Blackstar and I realized that
the I.S.F feature and the reverb with no spring pan meant that it was actually a hybrid. None the less, I assumed that these were "add-on" circuits,so to speak, and I tries it out. Needless to say I liked the tone, and the little box had more volume than I thought possible being rated 1 Watt. It was on sale( $100.00 bucks off ), so I bought it without much thought. All was well for about 8 months, and then it just died with a wimper upon starting up. After the initial warm-up period I noticed zero
sound. I looked down at the amp just in time to see the red power lamp slowly fade out. Although I thought that it was still under warranty, I decided to at least check the fuse(s ?). I took the back panel screws out and couldn't get the chassis out. It took some wonderment to realize that the 2 screws that go through the carrying handle had to come out as well. It came out easily then, so I looked for a fuse. I finally found the 100 volt glass fuse in a hidden compartment within the
female A.C. socket. It was good. That I didn't like. I looked at the tubes and they looked brand new, not that this means much. Then I scrutinized the (YUK) P.C.B.
After an extensive visual, I found the High Voltage fuse. A very small plastic cylinder with no markings. At least the board did i.d. it as a fuse. It was soldered flush to the board, so I knew that I'd done all that I could do. The amp was returned for repair. Two Blackstar techs that i talked to alluded to the fact that the Ht-1R is a "trash" amp. This disturbed me. They were saying that it would not be fixed, but replaced. My thought was what would one do if one of these amps blew up in the 13th month, buy another. I finally found out that this policy is for warranty work only. I guess it's just cheaper to replace them, which makes me think that they aren't the easiest circuit to troubleshoot. Anyway, it took a over a month to get my replacement. Like the fool that I am I picked it up, and took it home without playing it at my local dealershop. When I got home I absolutely cranked it up for about 20 minutes. It amplified fine and the tone was good, however I soon found that the reverb did not worl at all. Now I'm waiting again. I did carry on some correspondence with Bruce Kier, Blackstars chief engineer. He told me that all amps at blackstar have to pass a rigourous "end of line" QC battery. How does a non-functional reverb get by ? I also found out from him that the first stage of gain is an op-amp. So much for my theory about the solid state circuitry NOT being in the actual tube amplification path. I will say that the 12au7 dual triode as a power tube, with the two triode sections of that one tube operating in push pull, is pretty ingenious. Well, i hope that I wasn't too long winded with my story. I hope that the info is useful to somebody. The forums are pretty rife with Blackstar QC problems. so buyer beware. May your tubes never dim, Tonequester.

[Chuck H]

. Well, i hope that I wasn't too long winded with my story. I hope that the info is useful to somebody. The forums are pretty rife with Blackstar QC problems. so buyer beware.

It was long winded. FWIW forums are rife wih problems from many manufacturers. I don't think the number of Blackstar threads is disproportionate. Blackstar's original game plan was to offer hand wired "boutique"-ish amps that were designed by them, made overseas and QC'd by them. To offer the public a better than average product at a better than average price. It worked very well for a while. Then the inevitable cost cutting starts. PCB's and silicooties start creeping into the designs. Maybe Blackstar even stops designing and just "approves" SRO's from the Chinese manufacturer. In the end it's just another in a long line of run of the mill imported amps. FWIW I had a problem with a small Mesa amp about fourteen years ago. They opted to replace the "amp" part of the amp, chassis and all, rather than repair it. That sort of warranty service avoidance has been common for a long time. Even domestically on occasion. And with PCB amps and Chinese labor being so cheap, almost every amp company has the "replace, don't repair" policy on many models. We've seen this sort of thing happen to the appliance and home electronics markets too. It's the consequences of the Chinese manufacturing machine as set forth by US and Brittish corporations.

[tonequester]

tonequester here.

Thanks to Chuck H for the reply. Sorry for being long winded. I'll keep that in mind when posting. I fully agree with you in summing up the situation with QC and service in general. The Blackstar is only my second new amp in 32 years. The other being a Fender Deluxe which never faltered. My only real gripe with the whole situation is that i can't get my hands on a schematic,nor even anything close to a real spec. sheet. I guess that we all must remember Caveat Emptor. You know, I lost a good job as an electronics assembler years ago. The job and the company went overseas. This has been going on a long time, and I should have expected as much. Thanks again for the reply, it is appreciated. tonequester

[Enzo]

Blackstar is distributed in the USA by KorgUSA, is it not? Have you contacted THEM and asked if a schematic can be had?

The Blackstar HT-1R is on the replace only list for warranty, but there is a schematic on the service site page, so one is available at least to service centers.

Most manufacturers have a replace only list, it isn;t just Blackstar. IT has nothing to do with repairability or reliability, it has everything to do with the cost of the amp. If I solder something on those amps, they pay a $50 warranty service labor. Their cost for the entire amp is WAAAAY less than that. SO instead of paying us $50, they'd rather just replace the amp. It has nothing to do even with servicability. These are small, not complex amps. IN other words, don;t read anything into that replace policy other than $$$.

DO not repair lists generally cover the entry level product in a brand.

And I urge anyone not to make generalizations from a sample of one amp.

[diagrammatiks]

Blackstar is distributed in the USA by KorgUSA, is it not? Have you contacted THEM and asked if a schematic can be had?

The Blackstar HT-1R is on the replace only list for warranty, but there is a schematic on the service site page, so one is available at least to service centers.

Most manufacturers have a replace only list, it isn;t just Blackstar. IT has nothing to do with repairability or reliability, it has everything to do with the cost of the amp. If I solder something on those amps, they pay a $50 warranty service labor. Their cost for the entire amp is WAAAAY less than that. SO instead of paying us $50, they'd rather just replace the amp. It has nothing to do even with servicability. These are small, not complex amps. IN other words, don;t read anything into that replace policy other than $$$.

DO not repair lists generally cover the entry level product in a brand.

And I urge anyone not to make generalizations from a sample of one amp.

just gotta say hold on there for the small not complex part enzo...



It's no 8 channel midi head...but it's no champ.

[Chuck H]

Complexity is relative. I'll bet it's cheaper, in labor and materials, to make a Blackstar HT-1R than it is to make a Champ on an eyelet board.

[diagrammatiks]

i don't think it would cost them much to make it at all.

It's barely a valve amp.

[Enzo]

And that is the point, they cost next to nothing.


No it's no Champ, but it ain't an AVT50 either. More complex than a GX15 Crate, sure, circuitwise. Lotta stuff on that board, but like three dual op amps and all the resistors and caps that go with them just for the headphones. The thing about relative complexity is that one throw-away board and the entire innards are replaced. No multistep assembly or anything like that. Bolt, bolt, push, push, nut, nut, it's together. Only hand soldering I could see offhand was the output jack.

[tonequester]

tonequester here.

Thanks to diagrammatics, chuck h, and enzo for the replies to my post. On the Blackstar website, under FAQ's they specifically say that they don't offer schematics to the public for safety reasons. I don't know what "service site page" that enzo referred to but I'd like to know exactly as I would really like to get one, and perhaps one could be printed off of that site. I wouldn't have a problem paying for one for that matter. I would like wise, greatly getting a decent spec. sheet. They were returning my e-mails(Bruce Keith, cheif engineer) until I requested a spec sheet. The manual that comes with the Ht-1R is 4 one sided pages, in English. There are also copies in German, Spanish, french, and Japanese. I feel that if you are a beginner, you probably won't be buying this amp. At least when I first started practicing, I popped about $40.00 on a Fender Squier S.S. 15 Watter. Blaqckstar sure doesn't advertise this amp as a fine starter amp. At least I know that the external output is 4-16 Ohms. I do understand your take on the economics of the situation well. i lost a good electronic assemblers job years ago because the company went to Indonesia or Malaysia, I can't remember which. Actually,
I don't believe that building a cheap amp for high profit margine is a good excuse to be so secretive about specs. but I'll buy their safety concerns on the schematic thing. I do know folks that would stick a screwdriver in a live tube amp with a finger on the business end, standing in water. Maybe I'm the Lone Ranger here, but i like to have as much info on the equipment that I use as possible. I keep a note book on each piece of equipment. That's about it for me. Once again I give thanks for each reply, and the time and effort that it took to do so. I already feel part of "the Gang".

[Enzo]

You went to the Blackstar web site, but I suggested going to the KorgUSA web site, or better yet, much better, CALL Korg USA in New York. Just becasue Blackstar itself won;pt hand out the drawings doesn't automatically mean no one else will. Korg may indeed say NO, but we won;t know that until we ask.

I am an authorized service center for Blackstar and other brands. There is a web site for service centers, it is to that I refer. It is not accessible to the general public. I mentioned it to show that the schematic is at least published and available at least to some. There are many "do not repair" little amps that do not have schematics issued at all. SO if we call the distributor, at least we know he HAS the schematic, whether or not he will send it to you. I am bound by confidentiality rules not to distribute the drawings without permission.


Some companies hand out schematics, and many don;t. One of their main concerns is that giving you the schematic is tacit permission for you to be working inside the amp. If you electrocute or otherwise injure yourself doing that, THEY are now in the liability loop. Another concern is that when someone of unknown ability tries to work on it and fails, they will likley come away thinking. "Damn cheap Blackstar amps don;t work."


Try getting the schematic for your car. $75 later, and you have the service manual with the wiring diagram, but the computer or control module? Still just a box with wires coming out.

[tonequester]

tonequester here.

Thanks for the "scoop" Enzo ! I really appreciate your expertise and the sharing thereof. I will contact Korg. Perhaps, if you find the time, you could give me your opinion on the "project" that I had in mind for that HT-1R. It's as much for the learning experience as it is for the possibility of taking advantage of the fine tone of the amp,
while getting more volume in the end. I like the tone of the amp best, on the clean channel, the gain set at about 25-30%, and the volume maxed out. I had the idea(dumb ?)
to build a 20-30 Watt power amp, in kit form, and to use the little amp as a "tone module"/"pre-amp for the power amp. I don't want any tone coloration from the power amp,
just more output/volume. It would be kind of like miking up to a P.A. system. I've been told to use an emulator, but from what I've read about them, they can adversely affect
tone. I don't know if the Ht-1R's emulated output/headphone jack would be considered "line out". This is one of the reasons for my desire to get more in-depth specs for the amp.
It seems that I have three choices for such an output: the emulated output/headphone jack, the 4-16 Ohm ext. speaker jack, or the speaker output itself. I believe that the last two mentioned would be the same thing, but I'm not even sure about that. There are alot of reasonable s.s. power amp kits out there, and they usually have pretty in-depth specs
listed. Some are single i.c. circuits, and some are mosfet. Most of the ones that I've looked at on the net have low harmonic distortion, so they should not color the tone of the
Blackstar as long as one does not overdrive the S.S. amp. The kits range from about $15.00 to $50.00 depending on what all is included among other things. If you get the chance, once more, I'd appreciate any input(np pun intended) that you might have. If it's a stupid idea, for any reason, let me know that. Like I said in my first post, I'm much
more the tinkerer than the tech. That's at least for now. This is the only kind of "benchwork" that I can afford to do now, and at least I've had good success with kits and mods.
Thanks again for ALL of the help. Tonequester.

[diagrammatiks]

There's been some work done reversing the ht1 and the ht5. Enzo probably knows it a lot better then I do.

They share many of the same circuit details as the blackstar pedals.

For the ht1 and ht5 the signal path is something like

op-amp - op-amp - fet - fet - 12ax7 - op-amp - op-amp - op-amp - opamp phase splitter - power tube.

you could build a power amp for it but it would be much easier to get the blackstar pedal and a power amp if you like the sound that much.

[Enzo]

Nah, I don't know them other than by schematic.

I would say instead of listening to internet opinions (This shouldn;t work because I've heard bad things about emulators, for example) COnnect it up and HEAR what it sounds like. Got a line out? Good. Connect it to some other amp you are considering. Does it sound OK or not? Sometimes some aspect of something that someone doesn;t like can be corrected by turning a tone control a little. You never know until you try it.

[Steve Conner]

You asked about increasing the power of the Blackstar. You may be interested in this project that I did recently.
http://scopeboy.com/scopeblog/?page_id=96

Schematics are linked near the bottom of the page. Someone asked me to draw up a standalone version of the output stage, so I've done that too. It's supposed to accept the speaker output from a flea-powered amp directly.

[tonequester]

tonequester here.

Greetings to all. Thanks to diagrammatiks for the signal path. More s.s. than I ever would have imagined......ever. There's more to the term/label "Hybrid" than
I realized. I'm getting too old. Thanks Enzo for the common sense check. I have the feeling that this quality is not lacking in your work, or anything else. my only concern with the emulated output/headphone jack was whether if it by definition is a "true" line out. It seemed to me that the impedance for a headphone jack would be in the area of 32 Ohms. I had read that originally, line out was set at 600 Ohms, and of course I don't know what the Z actually is on that jack. It may be considered line out no matter what Z is
for all I know. I wasn't worried about bad tone. I just don't like working "in the dark" so to speak, and causing damage to either amp was my biggest concern. This to may be
impossible, and bad tone may be the only concern. Thanks again to Steve Conner. I AM interested in your mentioned project. I have written the "location" down so it can't escape me, and tomorrow I will give it a thorough checking out. I must take the opportunity to say that I really enjoy correspondence with one and all here. A mind is a terrible thing to waste, and you guys are keeping me on my toes. Until the next opportunity, good luck, and good life. tonequester.
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