just some curiosities about symasym4

Status
Not open for further replies.
Jump to Latest
#41
Hi Andrew,
You can add many more amplifiers to that list. All with "that" transistor sound. Poor description but you get my drift.

Hi Mike,
Thanks, you decoded me properly. 😉 I expected you to say more about this technically.

Hi keantoken,
My style is to inject some humour. It does not go over well all the time. No need to worry about anything you've posted.

Op amps are available freeeeeee! Junk audio gear is loaded with parts. Cassette decks sometimes used polystyrene caps too. The TL072 is popular and you will find many. There are a ton of other good chips. Do not sell Japanese numbers short either. Some are quite good. So start making you "junk box". A term familiar to all older techs. It's just as valid today.

-Chris
 
#42
I forgot about junk! Let's see... I have taken apart an old 1950's TV, I guess I could probably get some good parts from that. The problem is, (another one? boy am I a wuss) I don't have a soldering iron hot enough to desolder everything. All I have is one of those horrible cold heat irons that only gets hot enough to bead up some small solder wire. Someone probably stole my other one... Thanks for reminding me about that!

:cheers:
 
#46
My family doesn't believe in credit cards because the bills add up very quickly and we don't have money to spare. We don't care for internet money services either, so about our only way of buying anything off the internet is, if nothing else, using our diplomatic tongues to persuade the greedy merchants into giving us what we want free! And that rarely works, when we are so desperate as to use this silly method.

NOTE: This information may not be completely true in the latter parts and therefore cannot be used to judge us about our money, income, expenditures, or any other monetary attribute.

PS: I just got FireFox 2.0 candidate 1 and it works like a dream! It has a very useful spell check feature and is very handy, that is why I, evidently, am so happy. I would recommend FireFox to any member who is conscious about their spelling. Get it here:

http://www.mozilla.org/projects/bonecho/all-rc.html

I am not sure if you have to login to get it or not, but it's free anyways, so take a go at it

😀 :cheers: 😀
 
#47
Hi keantoken,
I can see your point, but reverse your positions with the merchants. I doubt strongly you would gladly ship parts at no charge, or you would be out of business quickly.

I ran a service shop for 16 years. I think you will find that many business owners are kind hearted, but they too are short of funds. The biggest difference may be that you have more time on your hands than they do.

The biggest problem is a certain element of the population that figures you are rolling in dough, so they figure you won't miss the odd $100. That is a percentage per year that they fight with. It is one of the factors that cause overtime work attempting to recoup those needed funds. Theft from family time.

I don't want to hear the term "greedy merchants" or anything like it from anyone again. This shows a very poor understanding of other human beings.

No, get a soldering station and strip parts from junked consumer goods. I think that is how many of us obtain a lot of parts. It sure is nice to work with new parts. I did buy new ones for the Symasym because it deserved them, but used will work as well as some members have done.

-Chris
 
#48
if you must ....

if you must have tone controls and you are set on a feedback design 🙂Popworm: mlloyd1 also ducking for cover since MikeB has improved his aim by now 😉 ) , look for the APT1 preamp schematic somewhere here and extract the tone control circuitry. it has some useful features.

mlloyd1
 
#49
sorry, anatech... I kind of forget about how diverse things can get sometimes. I try the best I can to get thigs right, but I get things wrong a lot of times because I am trying to inject some humor, and end up offending someone. I can only hope that the knowledge and understanding of my fellow DIY'ers will not fade away in my presence.
Despite my attempts to fit in and be like everybody else, I cannot settle my differences all of the time and be like the rest.

One thing I do know: There is no such thing as a normal person - Ive never met one in my life. To be normal is to be perfect, and is unattainable by any human action or thought.
 
#50
Hi keantoken,
No problem. We are all bent in our own little ways. We do have an international forum and many times a statement can be looked at in many ways.

But, we are anything but a homogenous mass of like individuals and we all have our "buttons".

You fit in fine.

So the first thing you need to do is get a soldering station and go harvest some parts. As you accumulate more parts, the need to organize them will surface.

I used to take apart TV's, the really big tube kind. I got speakers, transformers and .... tubes. Not to mention the clipped out resistors and capacitors. I took everything because I had no money and no parts. It took only one summer before I could build things and have most of, if not all the parts. It just takes time and determination. These days stereo's would be a better bet. Some may be repairable.

-Chris
 
#52
> jfets in the inputstage would be really interesting, i was too anxious to try the sk170 in symasym, their 40v max vds is too close to the limits for my taste...

You can always cascode them with MOSFETs, but how about running another set of power transistors off the unused leg of the second LTP (a la Nelson Pass)? Then you can lower the rail voltages and the 2SK170s would be just fine.

But then the next question would be why not FETs all the way?


Patrick
 
#53
Hi JojoD818,
I normally use a preamp. I like real preamps with gain and power cords. 🙂

Hi Patrick,
I can see cascoding the diff pair (and will). I wouldn't use FETs for outputs because of the gate charge and a big discontinuity in the transfer characteristics. Not my cuppa. BJT outputs are currently the way to go for reasonable dissipation in lower power home amps.

-Chris
 
#54
> I wouldn't use FETs for outputs because of the gate charge and a big discontinuity in the transfer characteristics.

The ASR Emitter is known here for good dynamics, and uses FETs (2SK1530 & complimentary). One can also name a few FET designs by G. Ball, E. Borbely, C. Hansen, N. Pass, ......

Even JLH argued for MOSFETs (p.171, paragraph 1, Valve & Transistor Audio Amplifiers, JLH 1997). And of course the latest book by Kaneda is all FETs (and tubes), both Class A & Class AB.

A matter of individual taste.


Patrick
 
Status
Not open for further replies.
Top Bottom