Sunday, November 12, 2017

Reviving an AIMS Producer

AIMS was a maker of amps that was around for a short time in the seventies. It is said that it was started by a couple of refugees from Fender but I have no way of verifying that.

That said the VTB-120 is quite similar to a Fender Bassman with massive transformers and a pair of 6550s running at about 530 volts on the plates. I may have mentioned this amp before but it was recently acquired by a friend of mine and brought in for some needed maintenance.

Here are some pictures of what I found plus a shop sketch detailing what it was, what it was supposed to be and what it ended up being.



20 uf 600v capacitors are pretty hard to find and expensive to boot-the last one I bought was a Sprague and it ran me thirty dollars.

So what I ended up doing was some math and some research, and a liberal borrowing of  news from Fender schematics, and I ended up with two pairs of 100uf 350v caps in series with appropriate balance resistors-much better than the bodged 220uf axial snap-ins that are in the picture.

Calculating capacitor value is the opposite of calculating resistances.

With capacitors in parallel the capacitance is C1 + C2  and so on and the voltage rating does not change. When you place two capacitors in series as I did the sum is half the capacitance and twice the voltage rating-and you should have balance resistors. So, two 100uf 350v capacitors in series is equal to 50uf at 700v. You can calculate this by using this formula:

 Ct=C1xC2/C1+C2

He'd said it was making strange noises and that proved to be a loose phase inverter socket which I plan on repairing tomorrow. That and a bit of bias tweakage to get the level down a bit will be helpful as it is drawing slightly too much current for my taste..

More pics tomorrow.

New power supply configuration.




Friday, November 3, 2017

More Blackstar Stuff

I've been wondering about the subject of Blackstar amps and their nonrepairability. In doing so I found this post on TGP by a fellow from southern Indiana and it sums up my thinking on the matter.

I recently bailed on two of them, and we've been talking about the right to repair. Also, my right to make a living saving things from the landfill.

Take it away, member Thorny64.

I have played a few of these in the store, and they didn't sound badly. Marshally, with a LOT of gain. Clean channels. Seemed to be nice for the money.

Who am I? I repair amps, and have for MANY MANY years. I also have built amps as well. I work primarily with tube amps. I have been an authorized repair person for Marshall, Fender, Ampeg, Crate, Kustom, Peavey, Mesa, and others - but right now I work independently. I have built and repaired for a few big names too. I get a lot of referrals. I get a lot of amps that people have taken to one or two other techs first. And I know enough to say I certainly don't know everything. I know and recommend other techs too.

I knew it was a matter of time before one of these came into the shop for repair. I see most everything eventually. I have a poor customer's HT soloist 60 head in for repair, and I traced down a problem that is keeping it from working, but can't trace it to a component and I get NO support from blackstar on anything. Even if I could, I could not likely replace it. (I fear there might be a short inside the board, but I can't afford to take the time and charge to trace this down, it is not readily apparent). They do no not respond to requests for information. I can't even buy another board and put in this thing. They apparently only have guys that sell amps and are not concerned about people after the sale. And definitely not concerned about people who currently own their amps (or future owners).

This has two preamp tubes (one each channel), and a whole bunch of solidstate preamp and phase inverter components. Construction wise, it is very much like looking at your computer mother board and throwing in a few tube sockets mounted directly to it (bad idea). Maybe some models might have a tube phase inverter (I haven't seen them all), but this one certainly does not.

This is made with a LOT of surface mount technology. This has high voltages running through it. When there is a problem (if it is not under warranty) you basically throw it away. If it is under warranty I bet they rarely fix them, they probably just replace them most the time. Most amps will eventually have a problem, and when this one does, you toss it. I imagine the cabinet and speaker are worth something, maybe the transformers (not sure about that since I don't know if the power transformer has enough specs to drive more than the two preamp tubes. An amp that is built like this is simply disposable. It is sad too, because it sounded decent to me (well the ones that work in the stores did). I would not buy them. I would steer clear of them. I recommend avoiding them.

Compare them to a another cheap amp, lets say a bugera - bugeras are built MUCH better and cost the same or less. Bugeras are usually all tube (except reverb in some, and some may have a diode or two depending on which amp they are copying the circuit from). I can fix Bugeras - I have, and I have played some that with a little tweaking sound fantastic. This one certainly turned out to be a black turd. I thought they had a lot of promise too.

Compare it to a car - if the blackstar were a car it would be a good running car with a lot of features at a pretty good price. It would handle pretty well and may be great if you are very lucky and don't drive it much, bump into anyone, or hit a chuck hole. But if you ever need to do anything besides change the spark plugs, you have to replace the whole motor. And if you try to reach the dealer, you don't get a response from the support department. So you can't even buy a motor. Your car has one thing wrong with it, well, you are left trying to take the wheels off of it and stereo and get whatever you can get out of it and buy another car. And guess what? It WON"T BE THAT BRAND EITHER. They are doomed.

All these guys that love theirs, well, they haven't had a problem yet. Because when they do (they likely eventually will) and it is out of warranty they will wind up throwing away their amp. I bet they are not OK with that. I wouldn't be. Blackstar's are way too expensive to do that. If you already have one, I am sorry. I hope you never have a problem with it. The guy that bought this one says it was $700 - and it was absolutely wasted on this amp.

And trust me guys - there is NOTHING I would want to copy on this amp (technology wise). In fact, it is a lesson in what to avoid as far as what I am concerned. In these cheaper and feature filled amps, they pack a lot into a little package for not much money, but even those usually can be worked on. These can't. If they would sell the board to replace in the amp, MAYBE the customer will do that - but they don't even offer to do that.

I never post opinions this strongly, but this time I do. I hate putting time in to repair a product and can't because of the company won't support it. It almost never happens. Usually with tube amps I just fix them, but this one can't be economically fixed and blackstar has not helped.:FM

I say if you like yours and it works, GOOD FOR YOU. I am glad. You may feel guilty selling it if you ever do. But if you don't own one I say
AVOID. AVOID. AVOID.

And this:

I will preface this by saying these opinions I express are my own, and not reflective of those that operate this forum. This is based upon my hands on with ONE amp. The rest I base on corroborating information found by doing google searches. I bet there are those that would like to know how their amp is put together and what they may be dealing with if it breaks from someone that knows (not a casual player that unbolted his amp and looked inside). Half of what you read on the internet is a bunch of bull, the other is not and it is hard to tell which is which. I have NOTHING to gain other than I'd love to get this one customer's amp fixed. And if I can't, I'd love to make sure that everyone knows. There is NOTHING in it for me. I don't even own one (and I wouldn't).

No comparison between the quality of a Diezel to a Blackstar. Diezels are built like a tank.

On Blackstar's website is a link to UK repair centers. There wasn't a direct link to US repair sites as stated. Plus to do this, you have to be sign up for an account - why? Just to find out who to talk to to get parts or a repair? Trying to find it for the US eventually routes you to Korg. Then you have to email Korg and hopefully they get back to you. Still no repair sites. I went on Korg's site and checked theirs. Theirs is who I called and got no answer from. That is a little different than a single click on a website.

The differences between Blackstars and Bugeras is that Bugeras can be repaired - I know - I have repaired many of them. They have been sold here a lot longer than Blackstars and there are a lot more of them around here. I think they are a little less expensive than Blackstar too. This is despite being fairly inexpensive tube amps, they really are not that bad. They are no cheaper built than the Blackstars. They aren't more or less reliable really that I can say, but I can say they are generally *repairable*. I never had to replace a board in one, not saying that couldn't happen. Most of the problems I found were normal things, usually blown tubes. I don't have to go back to Bugera and ask for anything to support them unless maybe channel switching or similar. Most amp techs wouldn't for most things.

As far as links to information, do your own homework! Google it! Search "Blackstar Amp Repair", or "Blackstar Amp Problem" and see for yourself. They are all over the place. Just because I don't supply you links that you can find yourself does not imply that I am making this up. See for yourself, I am not. Most say they like the tone and features, but don't like the problems they have to deal with when something breaks. I looked things up before I post such things - there is always the chance that when you encounter something like this that it is a "one off" event. But I found others that already ran into this. In fact I have never slammed any company like this before. I don't intend to start flame wars. I feel I need to warn people about this. I have also read accounts of people having problems with boards shorting - no fix for that except another board. I presume most of those didn't last past warranty and were replaced. But that is a design issue.

It is not a question of being able to repair one, it is whether it makes economical sense to do so. Given enough time I could reverse engineer this *stuff* (chosen word edited so as not to offend sensitive ears) and figure it out but life is too short and no one will pay for it. I shouldn't have to reverse engineer it just to fix the darned thing. I am pretty sure the solution for this is another main board but the real offense is Blackstar doesn't even answer the *mail* - so a more appropriate name may be blackhole amplification.

Most people don't have an "authorized repair center" for korg in their back yard. Korg is the distributor in the US. Limiting repair info AND PARTS is a tactic that forces some buyers to trash their amps when they die, or pay HUGE bucks and ship off to a service center that will only REPLACE THE WHOLE BOARD anyway. Korg want to sell amps they don't want to fix them. These guys don't fix problems like this, they REPLACE them. I know, I HAVE BEEN a service center for the huge list of equipment providers I listed in the previous listing. As far as being a repair center - it is a losing proposition with a company like Korg to most shops. I have worked on repairs for them in the past when I was doing authorized repairs for Marshall. But their current policy is you wind up having to repair anything Korg sends your way - keyboards, blackstar amps, and *used to be Marshalls*. Repairing amps for warranty you are imposed a LOT of restrictions. I choose not to work on synthesizers, FX pedals, things like that I will lose money trying to support. It *might* make sense if there were a large enough volume, but there isn't in this market area. Not everyone has a nearby Korg authorized service center, and not every center will work on a blackstar amp either (although they are supposed to do so). So if you get one, you may be traveling 150 miles like the guy I recently looked up did to get his amp fixed (google it).

So, I get to tear down this guys amp, find the problem, and try many different ways to find a way to get what I need to fix this amp (economically) and am unsuccessful. I still charge him a bench fee because I have spent hours on this. I have spent well more time trying it track down and get a part than I would have fixing it if I had the part. The part? The whole main board! That is what a repair center would do. Either of us could do otherwise, but it would take too long and cost too much.

You are right in that this is how Blackstar chooses to support their products (it is NOT a good way - doing this to your customers or even to those they sell their amps to).

I am right in this is what happens when Blackstar chooses to support their products in this manner.

I don't really say they are less reliable - all amps eventually have problems. I haven't had many of them come through for repair. But this one can't be repaired without replacing a whole board. They are difficult to find a repair center in the US, and when I try I still get no answer. Their actions show that they are more interested in selling product and not so much in supporting the product. If you get in this situation you are out of luck unless you have a good authorized repair facility very close to you and one that won't charge you a lot to replace the entire main board of the amp. This is not a problem they would likely troubleshoot to a component on the board - they simply don't do that if it is something that takes much time.

Now - take another company - Mesa. You call them, you get help. It is not that Mesas don't have problems, they do and so do most amps eventually. But they have the attitude they want to see their amps fixed and working. They know that seeing someone playing a Mesa is some of their best advertisement. And from what I have heard, Mesa is VERY protective of their designs without resorting to the support non-sense Blackstar puts you through. Blackstar does not have that commitment at all here in the US. They didn't respond at all to me, not even referring me to their US distributor Korg when I tried to contact them directly. Not that that would actually help either any longer.

So - no offense to you - I don't say anything about you. I only say professional comments about the amp, its sound and features (generally good) and its build quality and repair-ability. But you imply I don't know how to fix it, when I certainly DO. It is a commodity product that is much like any TV set. You narrow it down to the board and swap the board. That is the way it is done. And my efforts to get info or a part to do this from Blackstar amps has not been responded to by them. Since Blackhole amplification chooses to support it this way, I will recommend the user buy an amp that is supported better and that can be fixed - so his money will not be wasted. Other amps in this price range you can generally fix - unless it is a line6 or something. Then you just throw it away and get another. I guess blackstar tube amps are that way too now. It is OK, as long as the customer knows what he is getting into.

Your analogy is all wrong. We are not talking mercedes and lawn mowers. We are not talking even apples and oranges. Serviceability on these amps is extrememly limited. And they have made it difficult to get service limiting your options (if you can even find your options) if you are not the original owner. So you can make light of it. This guy isn't happy and it has nothing to do with me. Blackstar's actions show they couldn't care less for people that buy their amps used and they make them so it is more economical to dispose of them rather than fix them should they have a problem like this. I don't know for certain how prevalent these problems are, but any problem like this will result in the need for a new board, and that is just poor design or build quality. If you want to keep buying disposable amps good for you. But I think they cost too much for that, and it is their actions that make it this way.

The problem may the Korg/Blackstar relationship, but Blackstar hasn't even gotten that far. On my own, I searched and found the Korg listed authorized repair center (the closest one nearby) and got an answering machine. I left a message. I never heard back. It was an outfit I have never heard of and I have been here about 15 years in the business. Kind of makes you wonder if they still are a Korg Authorized repair center or if they work will work on tube amps. I have hours of going round and round in circles and getting nowhere. I just want the guy to get his amp fixed, if not by me then by someone else or someone that can sell me the part or will fix it for him without sending him to hours away to Nashville. Blackstars are not really that special to warrant that kind of treatment.

I WANT THIS fixed for my customer. I know the amp can be fixed. I don't know if the new board will have the same problem as the old one or not, but we are not even getting that far. This guy would like to get his amp working. I am sure he will sell it as soon as he gets it working because of these problems. I am trying to get it fixed. Blackstar so far is zero help. I didn't expect this at all. Maybe he can drive it to Nashville, Indianapolis, or St. Louis and get it to an authorized repair facility if they have one there that will work on it. The one I called didn't call back. But that would cost hundreds in shipping, and/or a whole days worth of driving. And they don't fix them while you wait nor do they typically stock boards. It will take weeks. It may take me weeks to get a part from a distributor, but generally they will sell me one and the customer does not have to travel hours or ship large combo amps long distances.

But mistake or not, the buyer of this blackstar amp is out of luck no matter what option he chooses. What are his options?
1) He can ship and wait, and not know if it is worth repairing after it has shipped. This is a very heavy combo amp.

2) He can drive it, equally unappealing - expect two trips too and from - over 100 miles and X4 (to and from twice).

3) He can dump it and sell broken/for parts *huge loss of money - 90-95% and get something else - that guy won't buy a Blackstar again for certain

What would you do? Would you buy a Blackstar again if this happened to you? The old adage is "it is easier to keep a customer than to win one" - so blackstar expects to win one each and every time? I hope you have some other amp line to move them to, if they even want to talk to the place that sold them this again! It would be a really hard sell to get them to choose blackstar after this experience. Is it time to rethink this strategy? Or are you banking that you won't offend enough of your customers that you still will get by? Customers that deal with this kind of stuff are very unhappy and usually let others know. It grows like a very bad virus. The right thing is for Blackstar to do is to send me a board for this customer's amp. It isn't a big deal to me, I only get paid to put the thing in.

I just feel terrible for the guy. It isn't mine. I didn't buy it. I have no reason to bash blackstar even if it means there will be an amp that I may refuse to work on - it will only likely be a very tiny amount of what comes across my bench. Who knows - you MAY BE the worlds best tech out there. Maybe you have greater than a bachelor's degree and 20+ years of experience with more service center responsibilities And if so, please fix this amp - because in my working on them over 20 years now I tend to know what I am doing, but I can't fix things without parts (in this case proprietary parts). Can you? Does that make me stupid? Frankly I know I am not so it really does not matter what you say.

Although, I design and have built my own amps. I can repair for 20 years, including for professional acts. I have built amps that toured with them and/or are on their albums. I could be touring with some acts if I really wanted to go that direction (but I have a family and a home and don't want to be on the road)

Would I be your amp tech? Not likely if you had a Blackstar and needed anything more than tubes or a bias - or something very simple. I could even be a board swapper for you if they would sell me the board. But as it is it is generally un-repairable. If they want to you send it to a regional board swapper, then go ahead. Don't expect me to recommend a Blackstar though. It is all about what is cheaper to them, and I suppose this is the cheapest way to do things in the short run. Blackstars really sound good for the money in the short run. But it will cost them in the long run. I won't lose any sleep telling my customers they should look at something else - for all the reasons I state. I can't decide for them. If you think it is the greatest thing and that is a smart business model (as a consumer) then go on and vote with your dollars and keep on buying them. You can tell a person over and over again NOT to hit their thumb with that hammer, but regardless of what they think it is going to hurt all the same if they choose to believe you or not.

Also, I know a dealer that has chosen not to continue to sell Blackstar amps as well. If I were a dealer, I'd change too. I did not ask them if this was the reason or not. There are lots of potential reasons. I went to this dealer in order to try to see if they could buy me parts. I won't name names either, but I have no reason to say otherwise. Dealers wouldn't want to discuss a business decision like this publicly.

I have been disappointed by lots of amps in terms of quality, but most you can get fixed. Customers still expect that for one that costs like these do. I use the Bugera brand as an example that is probably cheaper and better overall from a guitar player and experienced amp tech's view. It may break just as often but I have been able to fix them. I think the only problem one of them has ever given me was for intermittent channel switching problem - the rest is all standard stuff. You can gig with them. They generally sound great with a little tweaking. I have not played or repaired every model of both product lines. I have owned several bugeras, tweaked them out and sold them. I wouldn't buy a Blackstar despite them sounding pretty good unless it were VERY cheap. I'd have to be willing to toss it if it broke. I am not saying it will break more often than anything else. I'd almost feel guilty to ever try to sell one used. They have this consistent design from what others have reported throughout this product line. So I make that assumption having only had the one in the shop. If you can report to me that the design is significantly different and more reliable with the other models than the soloist 60 then I will certainly listen. But what others (again, google is your friend) have said, they seem to be very similar.

What prompted me to respond is this current experience and looking online to see if others have had this issue besides me. So far, I have not heard anything inconsistent with what I have stated here.

The Blackstar way seems to be:
- Surface mount technology - not the most reliable/serviceable in a guitar amp.
- most guitar amp techs cannot work on it, not cost effective
- most repair shops simply must swap out boards - not cost effective otherwise
- this winds up costing more to fix and usually means longer times to get fixed
- make it worse by restricting access to information or parts
- this discourages amps from getting fixed

Why might they do this?
- probably easiest way to do things for them
- probably cheaper to not support hardware (short sighted)
- feel it offers some level of control (it really does not)
- encourage obsolescence - old amps out of warranty quit working
- non-original owners are not important to Blackstar

It might be supported a lot better in UK since they are a UK company. I cannot comment on there. But I can hope. 

Thursday, November 2, 2017

Repeating Myself With Seaidea

This is a little off the beaten tube amp and antique radio track but it is worthy of some interest here.

Recently my wireless system in the house got pretty tired and it appeared that my repeater had died. Another problem was that a wireless network I'd never heard of before has been stepping all over my somewhat weak wireless-it's OK here but very tired at the other end of the house-which is where I do my amp work and I depend on a computer there to host my library of schematics and answer a few questions.

In a way we should have expected this.

In the 1920s and 1930s many radios were regenerative or had a regenerative feature that would rebroadcast whatever they were tuned to. Remember all that movie schtick with the nazis locating clandestine radio sets via a loop antenna on top of a bread van? That was because of regeneration. It was fine if you lived out on the farm but in an apartment house with multiple families listening to different stations the problem was real.

In the 1930s Philco developed the first remote control for radios that they made-premium sets to be sure. You could sit in your favorite chair and dial in whatever station you liked, but if your upstairs neighbors in the apartment had a similar radio with remote you might be changing their station as well as your own.

The operative principle here is competing signals swamping each other-stepping on them as the CB radio aficionados called it.

Until the other day the downstairs shop computer chores were being handled by an elderly Dell workstation that had been built up out of junk parts, cheap crap from Newegg and the deceased CompUSA chain, and the carcass which I acquired complete with a Pentium 4 processor for fifty bucks at the Iowa State University surplus outlet. It did the job if you didn't ask too much of it at one time.

A friend of mine offered a relatively more advanced HP  tower in exchange for some amp work and we made the swap-kinda like Francis Gary Powers and the bridge more or less, exchanging prisoners at midnight.

I spent today getting it up to date but I still had the problem with a weak signal and my seven dollar Chinese wireless LAN card newly housed in the new-ish computer wasn't liking dealing with a weak signal. Sorting out the audio and video were relatively simple as the new tower had both functions built in.

The computer is the newer SATA format pinout so I could not use my nifty 500gb hard drive, DVD drives and my floppy disk drive. I guess the era of the 3.5 inch floppy diskette is finished around here more's the pity. I think I may be able to repurpose the power supply as the connections look similar.

To continue the thread, I'd purchased a Seaidea repeater on fleabay for about twelve dollars and it was this one. What it is is a simple receiver-transmitter that detects and amplifies weak signals before rebroadcasting them.

But you have to tell it what to detect and rebroadcast first.

So I still had it but it became apparent that the repeater had to be configured to work properly. This unit came with a good set of instructions and I won't bore you with the gory details.

What's required is to use your computer to address the repeater via a LAN cable, configure it, and you're done. I simply connected the device to my wireless router via the short LAN cable that the fine folks from Seaidea, the people who made this device provided.

Then, you take your newly recognized and configured repeater and put it somewhere about half the distance to the place where you want to connect.

It worked terrifically well. I now have five bars throughout the house and with any luck I am stomping all over my neighbor's wireless even as we speak.

If this is you, it's easy and all you have to do is make sure that your computer is set to recognize the wi fi repeater rather than your original network when logging on.

UPDATE:

Nothing's ever as simple as it appears on the surface. Because we were making such fine progress on the home network front we decided to secure our wireless system from freeloaders and moochers of all kinds.

After properly addressing the router to institute a security protocol, not only could I not log onto anything but my nifty Seaidea repeater quit working.

Several hours of bodging revealed that I had to first reset my new cable modem that Mediascam foisted off on me. In order to do that I had to wipe our whatever it had as settings and reestablish that. When that was done the same process had to be repeated with the elderly Cisco wireless router . Then, and only then, could I get the repeater configured to work properly.

Of course there was a benefit in all this because all that time the cable modem had been trying to establish a phone connection because I'd plugged the LAN cable into the phone port. That slowed things to a crawl until I got that figured out in the process of all this other silly shit.

All this took a good part of the day. It's knowledge I had no interest in learning and my spouse does not understand that at nearly seventy I do not want to waste time mastering knowledge that is of no earthly profit to me.

Of course it was after all that that the Tivo decided it did not like the new security settings and I'll have to contact Mediascam on Monday for the proper MoCA encryption key to make the search feature work properly. That means another morning shot doing battle with dunces and morons to acquire knowledge that is of no interest to me.

I mean, who gives a flying f**k what MoCA is or does?

Thanks, everyone. No one ever said.

Of course I missed the opportunity to rename our wireless network FBIvan3.