Electronics CE

[adamct]

Ummmm....yeah. I'm not asking Bottlehead to change their business model by making one unpolished video.

Anyhoo...I stand by what I said above. There is a world of difference between reading some general principle in a book, vs. learning about a project you are building yourself. But I think we've probably beaten this subject to death. Some see value in the idea and would learn something. Others don't. And it's moot since the team doesn't have the time.

 

[corndog71]

This reminds me of a conversation I had with a friend of mine who wrote her own songs and music and performed in clubs.  One night after a few too many drinks and watching her perform I tried giving her a little advice about something.  She responded with a very curt "Let's see you get up there and do it".

Suffice to say, this stuff isn't easy.  It takes time and effort.  A lot of information is already out there.  But if you really want to know, you kinda gotta suck it up and do your own homework. 

I bought a 1962 RCA Transmitting Tube Manual from amazon for $12.  Some of it was over my head but I learned a lot of basics that were never really clear to me before.  I highly recommend it.

 

[2wo]

Might have a look at the Valve archives. Things like parafeed are well explained there.

There are a number of projects there that are explained in great detail, some by current Bottlehead designers. I for one always reread the "Blues Master" by Doc Himself, each time I contemplate building a new amp.

If you really want to understand this stuff, its not hard but you have to do your homework. Once you get 1 or 2 things, the other 4 or 5 are like, oh OK.

How about this, have a look at the Valve archives, Let's pick an article and break it down. I will help, I bet if we ask Granger nicely he and others would jump in...John

 

[adamct]

Sure, that would be awesome!

 

[odamone]

I just wanted to chime in with a big +1 for adam's video idea. It's a small investment for a potentially big payoff. It need not even be an official BH video. Perhaps someone on this forum who has done their homework could discuss the circuit design for 30 minutes.

 

[earwaxxer]

The point is, there are probably many things that Bottlehead COULD do that would, in someone else opinion, be a good move for them. Those in charge decide on all these things, such as whether to advertise, sell dildos on the side etc. I think its ridiculous to tell people how to run their business. I, personally, think it would be good to get their kit reviewed in the 'mainstream' audiophile subculture. Who cares what I think! In a way, I'm glad they dont.

 

[adamct]

Whoa again! Nobody is "telling" anybody to do anything. Requesting, asking, begging, groveling: maybe. Ordering, telling, demanding, threatening: no.

I'll put my money where my mouth is. If someone wants to pick a good article (or articles) for me and others to read, explains the basics of the Crack circuit, and agrees to answer some reasonable number of questions, I'll pay them $50. Maybe someone else can kick in a few bucks, too. It has to be done publicly, in a thread here for all to read and benefit from.

 

[earwaxxer]

sorry Adam... I'm in a "mood". Hard week. Kind of frustrated..

 

[Mike B]

Crack is easy.  Direct coupled triodes.  You can see from the schematic how easy it is.

The input tube is biased by the LED.  The signal goes to the grid.  The load line is determined by the resistor or the current source (speedball)

The output is direct to the grid of the 6080.  Also biased by the load resistor or the current source.

The amplified signal is coupled to the phones through the 100 uF cap.

Done.  Keep the $50.  See how easy this is?

You have a DC circuit (bias) keeping the tubes in the active region and an AC circuit through the middle isolated by the (DC blocking) caps.

 

[Mike B]

No questions?  Good.

Now lets look at the power supply, the heart of all things electronic.

The circuit is called CRCRC as the filter is 3 caps coupled by 2 resistors.

The transformer delivers AC to the bridge rectifier which flips the negative half cycle to positive.  Now we have DC, but it's really rough.  The first cap holds the peak voltage, the series resistor reduces it and makes it more stable, the 2nd cap increases the stability and again for the last stage where we have the output voltage of 170 VDC.

The filter has reduced the DC to just a litle over the RMS value of the transformer, so it should be nice and quiet (low ripple)

Now I have one for you guys.  Lets see if you know Ohm's Law and how to apply it.

Using the Crack manual only and a calculator, tell me how much current the power supply (B+ only) is delivering to the amplifier.

 

[Paul Birkeland]

Perhaps the real solution to this conversation is to rehash Valve?

 

[docbob52]

I started this post and found the replies all interesting. Dan, you do have your plate full and production must be goal #1 for a small business and as wonderful as yours is. My suggestion is to pass this of laterally to an associate, review his work and offer it as an upgrade option on your website and you both split the additional profit at say, 20$ per kit. 

Judging by the large interest in this topic that might be some additional cash flow.  Grainier and  PB. Are you listening????

 

[Grainger49]

Bob,

Where it says "Old Fart" today it once said, "You Know I'm Not A Bottlehead Employee, Right?"

I am retired from Kimberly-Clark.  Retired again from a 6 month contract with them two weeks ago.

 

[docbob52]

Yes Grainger I know that you are not a Bottlehead employe. But you are active and I bet that after 6 months of retirement you will totally board as most are in retirment.  Reminds me of an 85 year old corn farmer in the Midwest interviewed on NPR 3 weeks ago.  The asked him why he was still farming several thousand Akers at his age and he said "Allthe old farmers I know that retired to the suburbs died of a heart attack in 6 months ". 

 

[earwaxxer]

So, Granger, I guess thats it. No more temp?

I'm a temp now, in 2 weeks I will be, finally, part time - a job share arrangement. I figure that will be what I need....

 

[Grainger49]

Nope, waiting for a call back.  I have been assured it will happen this fall.

Part time temp is a good thing.  Full time stops everything I have on my plate at home.  I think you have the right idea.

 

[mauroj]

I just want to preface this comment with the fact that I have not built a kit yet, but I have read some books on the subject and will be building the quickie soon, followed by a sex kit. The truth is, I want to know more, and I see real value in someone who is very well versed in the subject doing a video, breaking down a build into easily explained portions. To that end, should someone from Bottlehead ever have time to do this, I would be more than happy to pay for the privilege of accessing the video or videos. Also, I am not demanding these at all. I just would love them. Much like a video I watched recently of Peter Lederman from Soundsmith breaking down his philosophy on moving iron cartridges. I gained a lot from that video and I crave more, given his talent fro producing great products. Thanks in advance.

 

[Mmaxed]

I was going to stay out of this, but....

I recently completed my first kit a Reduction.  As I was putting it together, it dawned on me how much time and effort went into the kit.  Someone has to design the circuit, test, revise, test....  Then as I was soldering components in I realized how much work went into just the layout.  And it is already set up for future add ons.  Somebody has to write instructions that even I can follow, source all the components, organize, pack, ship, and I'm sure a lot that I am missing.  Then they put this wonderful kit to my door for a great price.

I guess what I am saying is that BH is doing what they do very well, and I don't feel it is their job to educate me.

Typing finger is tired.
Mark out. 

 

[Doc B]

Thanks, Mark. Kudos to PJ, PB and Josh for a whole lot of the things you mentioned. This thread is kind of funny to me because we have spent 20 years figuring out how to design kits specifically so that people who don't know how all the parts work can build them. That, in fact, is our specialty.

I do take that folks want to learn more as a great complement. And I consider it a complement that someone would ask us to help them when a library of text books has not. I'm just not sure how much curriculum we can fit in. Things are very, very busy here at BHQ these days just trying to keep up with the number of orders coming in.

 

[Grainger49]

You guys post questions In the TECHNICAL TOPICS folder and I'm pretty sure they will all be answered. 

Dan & Company write the best manuals I have seen.  You can't imagine how I appreciate that.  The first kit I assembled had both the instructions and schematic wrong!  That is inexcusable!  Bottlehead is light years beyond those instructions.

As Dan just posted, he intends to write to novices.  He used to test the manuals on his wife Eileen.  But now she is an experienced kit builder.  See, a double edged sword.