Check out my 200w Guitar Amp with KT90s

[VacuumVoodoo]

Tone and "great amp" is one thing. A transformer that overheats (good thing it got caught in time) enters the area of electrical safety. Talking of which, 750V HV secondary calls for compliance with some pretty tough safety requirements, a good deal tougher than our usual run of the mill under 500V toys.
The Dynamos look pretty well engineered on the outside, I hope the guts are engineered to safety standards. I say "engineered" on purpose to differentiate from non-engineered haphazard assemblage of wires and and components.
I wouldn't have commented at all on these aspects if it wasn't a commercial product.

[Prairie Dawg]

If the objective was to spread the word and get people talking/increase the number of potential google hits then the objective has been accomplished.

Ask Lindsay Lohan-it never hurts to beat your own drum, and any publicity is better than no publicity.

Having said all that they're fine looking amps and the 50 watter is pretty. Let's see the innards of it. If they're as sweet as the outside it should be a treat-that'll REALLY get people talking.

I think I've had enough of misunderstood moody geniuses who'll reveal the secret sauce for a large sum of capital or take deposits for amps that never get built and work that never gets done, or allege that they're channeling the ghost of Bob Crooks in a way that only they can do, to be revealed for a suitably large stack of cash.

I hope this isn't one of those conversations.

[Masco]

Not trying to be rude about it but we see right through the bullshit and could probably have your amps deciphered in about an hour if we really wanted to. ...I wouldn't buy an amp from you simply because it's obvious already that you don't understand them enough to build something worth my money.

Damn, is this what TAG is about? Lighten up man.

[Phil_S]

The topic didn't pique my interest until I saw it was up to 4 pages. Like many of us, I have no use for and little interest in anything over about 20-30 watts and generally build my toys for low wattage.

Whether I think this post is a troll for publicity or not is not really the point. What I want to point out is a basic tenant of behavioral psychology. If you have a troll, you feed the troll by posting anything at all. If you don't feed the troll, he will go away. So, if you think this was a troll, then you should not post. Even negative comments carry a certain kind of reinforcement.

This gives support to what parents have been telling children for generations: if you don't have something nice to say, don't say anything.

To put a fine point on "something nice" there is nothing at all wrong with giving a critique that points out flaws, bad practice, etc., as such comments should lead to improvements.

I think you know what I mean. Overall, I was surprised at the tone of some of the commentary on this particular thread. Ordinarily, the tone here is so civil I sometimes find it hard to believe such a place can exist. This one has some hostile overtones -- maybe with good reason -- but I won't judge. I think the mods erred in not killing the thread.

FWIW, that's my 2¢, even though no one asked

[Cliff Schecht]

Not trying to be rude about it but we see right through the bullshit and could probably have your amps deciphered in about an hour if we really wanted to. ...I wouldn't buy an amp from you simply because it's obvious already that you don't understand them enough to build something worth my money.

Damn, is this what TAG is about? Lighten up man.

No, not really, we're usually pretty lighthearted. And to put things in perspective I feel this way about 90% of the boutique handmade amps that one can buy for egregious sums of money. But most of them don't come onto our amp building forum and try to sell us their finished products. The ones that do get treated similarly, if not by myself then by others. Remember that we are a community that thrives upon members contributing information, so when somebody starts a thread that offers literally no insight into guitar amp building/designing then a few eyebrows will be raised (although he did get into his transformer design which we DO appreciate!). I think Phil has it right, the mods probably should have deleted this thread before it had a chance to turn into what it has.

FWIW I get what Dynamo is doing. In a market such as guitar amps much of the advertising is word of mouth. He's spreading the word about something he created and is proud of. TBH they are good looking heads, I'd be proud of them too at least in that sense. I wish Dynamo the best of luck with his amps and his company, especially being a fellow Texas builder.

My whole point (which maybe was lost in my late night grumpiness) is that I don't necessarily appreciate the way he is marketing his amps. This is what set me off so much. He is guilty of the same tag word peddling as every other modern amp company. Calling your 10x more expensive caps audiophile grade and resistors that give you "pure tone" and whatever amount of detail is pure marketing crap unless you offer some sort of proof that the capacitor manufacturers do not (they make these same outrageous claims). A funny bit of truth to his statement is that most audiophools won't give your products a second look unless they cost over a certain amount. If you don't charge a bunch of money for your product then it must be crap, right? (this is not pointed at Dynamo, maybe I'm digressing too much ).

The other thing that irked me was the erroneous statement that increasing the output stage power will increase the amps noise. As I tried to point out this is a flawed way of thinking, at least technically, which tells me a lot about the builders knowledge of the devices they are working with. Maybe Soldano and Bogner were guilty of not really understanding the amps they were building, but you don't see me or others rushing out to buy their early examples either. Heck, to that point Mesa Boogie's are the same way and I probably wouldn't own an early example past the cool factor. But that's just me and, once again, is why it's hard to sell an amp to an amp builder. That's like trying to sell a used car to a used car salesman or shoes to a shoe salesman. They are going to laugh in your face..

The other concern I had/have about the Dynamo amps are what Alex pointed out, that there are special building techniques that one is supposed to follow when working with HT voltages past a certain point. Open up any modern high power ham radio linear amplifier and you'll see what I mean. They have to be built a certain way (clearances, component choices, socket types are all dictated by this). If he does not follow these guidelines then he is putting himself and users in harms way. If something failed in his amp and hurt the end user then it would be his fault. This is the reason I don't sell amps usually, unless you go the full route and get CE certification then you are taking a huge risk with liability. I don't care how many warning labels you stick on/in an amp, if it hurts/kills someone then you are in for a world of legal issues (all moral issues aside). If Dynamo has this aspect of his amps in order, however, then once again I wish him the best of luck with his endeavor. If he is not up to snuff in this aspect then I cannot in any way stand behind his products, regardless of whether I would actually buy one or not, because it would be putting my friends lives at risk!

[Prairie Dawg]

Maybe when the builder referred to a 750v@600ma power transformer he was talking about a 375-0-375 item?

[VacuumVoodoo]

IMO 2x375V using full wave rectification instead of bridge for a 200W amp is technically poor and costly design. A Single winding using bridge rectifier will use copper wire with 1.4x diameter used on 2x375V for same current rating. Takes less space on the core, weighs less, has lower copper losses and makes the transformer cheaper.
I hope mr. Dynamo will offer some down to earth technical explanation of his thinking.

[TUBEDUDE]

I'm happy to see someone else enjoying the art of amp building. That's what creates sites. Such as this, the spirit of adventure and accomplishment. TAG, more than the others, is graced with builders that posess a great deal of collective knowledge, and a generosity of spirit. They will give that hard earned knowledge to help others that share this need to understand and create, and they should be viewed as the invaluable resource that they are. That said, this forum likes to see schematics, gut shots, and technical descriptions of circuits to either help diagnose problems, suggest improvements, or discuss the relative merits of a circuit. As a builders forum, this is our focus. The people here will give you some lattitude in expression, but with sales propaganda like claims, and no schematics or gutshots, well, responses like Cliff's are to be expected, and are appropriate. Don't show me the baby, tell me about the labor.

[rogb]

I'm happy to see someone else enjoying the art of amp building. That's what creates sites. Such as this, the spirit of adventure and accomplishment. TAG, more than the others, is graced with builders that posess a great deal of collective knowledge, and a generosity of spirit. They will give that hard earned knowledge to help others that share this need to understand and create, and they should be viewed as the invaluable resource that they are. That said, this forum likes to see schematics, gut shots, and technical descriptions of circuits to either help diagnose problems, suggest improvements, or discuss the relative merits of a circuit. As a builders forum, this is our focus. The people here will give you some lattitude in expression, but with sales propaganda like claims, and no schematics or gutshots, well, responses like Cliff's are to be expected, and are appropriate. Don't show me the baby, tell me about the labor.

I will adopt this expression, if you don't mind

Unlike Senor Dynamo, people like Cliff respond in other ways too, like offering to help another forum member, mccracer, who has eyesight problems, in getting together a talking DMM. Check out the post.

https://tubeamparchive.com/viewtopic.php?t=16251

mccracer has chipped in and offered me advice in the past, and I will always be grateful for that, but I can't help him on this project.
I wonder if our good friend, husky, can help here?


THAT is the measure of people on here.

If you want to be part of this community, chip in any way you can otherwise f*** off. I know next to nothing compared to the guys who frequent this place, but I try to help if I can.

Sorry if my bluntness offends but that is my true feeling on this blatant and really rather sad advertising.

[Jana]

Yeah, all well and good and what not, but have the Hinklefarbs been calibrated properly?

[Masco]

Not trying to be rude about it but we see right through the bullshit and could probably have your amps deciphered in about an hour if we really wanted to. ...I wouldn't buy an amp from you simply because it's obvious already that you don't understand them enough to build something worth my money.

Damn, is this what TAG is about? Lighten up man.

No, not really, we're usually pretty lighthearted. And to put things in perspective I feel this way about 90% of the boutique handmade amps that one can buy for egregious sums of money. But most of them don't come onto our amp building forum and try to sell us their finished products. The ones that do get treated similarly, if not by myself then by others. Remember that we are a community that thrives upon members contributing information, so when somebody starts a thread that offers literally no insight into guitar amp building/designing then a few eyebrows will be raised (although he did get into his transformer design which we DO appreciate!)....

I totally aggree. I felt the same about Dyna's "contribution" w/ my first comment a couple of pages back.
I recon I have a bit more hair on my tongue than you.