I'd suggest you slow down. Use your time away to research your project more thoroughly and start buying after you come back home.
resistors are just resistors.
Use a metal film type that has a tempco of 100ppm/C or lower.
Use 1% tolerance, this is standard for small resistors now.
Use good commercial quality. Forget about all the exotics where money that grows on weeds is required to finish a project.
We in the UK have access to 600mW @ ~£2.00 per hundred.
Some other countries seem to have 250mW, or 500mW. Choose any of these but try to operate then at well below their maximum power rating. aim for <<50%
For feed back resistors aim for <10%.This is often contravened by MANY layout designers. Putting two in series is sometimes better than using two in parallel, (voltage limit and voltage coefficient).
Some resistors will require to be high power. Wire wound are as good as needed, but metal oxide does for most. These are usually 5% or 10% tolerance. But match to <1% by DMM after you get a batch.
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That's good advice. This amp was a distraction for me, so I threw myself in really quick to keep my mind busy. I usually do far more research before I start something.
Thanks for the info. The resistors in question were for a high power application, so thats good to know.
I think I might talk to ours stores guy, and see if I can order my BOM through our work account. We seem to get discounted prices on alot of our equipment/ general grade parts. maybe it will even give me access to some parts with better tolerences.
Soldering the parts to the board is the easy part...to me getting the parts and putting together the case are much more time consuming.
I bought three double glazed windows (just the glass, not the frames) that way. I got about 70% off compared to a normal customer order.
Just an update. On top of the $80.00 UPS claims they will charge for freight, they also throw another 85.00 for paperwork processing on top of that at the door. So The bill came to $265.00 for shipping with UPS ($90 Tax, 0 duty, and $165 UPS charge). This is only for the 5U case, and PCB's.
To make it even worse, their customer service made me want to jump through the phone! 😡
Rant over.
New total is $1090.00 + the cost of components for the PCBs.
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Shipping in from the states, I've always tried to use US Postal/ Canada Post if
possible. Always found they have the cheapest rates and little paperwork (brokerage).
possible. Always found they have the cheapest rates and little paperwork (brokerage).
That's a lot of money just in shipping.
I tend to overlook how much I end up spending on hobbies. This is a situation where being disorganized Is actually helpful.
We spend our working days making something for someone else...the chance to make something for myself is welcome and worth it. Plus the cost of the amp you're building will get spread out over countless hours in the years to come.
I tend to overlook how much I end up spending on hobbies. This is a situation where being disorganized Is actually helpful.
We spend our working days making something for someone else...the chance to make something for myself is welcome and worth it. Plus the cost of the amp you're building will get spread out over countless hours in the years to come.
Thanks for the tip! I used UPS a couple of weeks ago for my new soldering station; and everything seemed reasonable. Lesson learned I guess. Personally I think it's the same as when Airlines used to advertise prices, and hide the landing fees!
You make a couple of great points. I know it is an expensive adventure, but like you said: the end result will be phenominal.
I'm very excited to learn all about the circuit, and hopfully will be able to speak confidently about all aspects of the build when I am finished. This forum has been a great help so far!
I need 33 with frames for my new place, 70% off would be fantastic 🙂 Think of all the amps I could build with the saved money!
I'm using 2x45V toroid. With 2x3x15mF (45mF per rail) and dual bridges it gives about 2x64V with 75mA bias and no load.
I use 2sa1930/sc5171 as drivers and mg6331/9411 as power transistors. Other transistors: LTP 2xSS9014d,
Q5-6 = ksa1015Y,
Q7 = 2sc2240bl,
Q8 = ksc1815y,
Q9 = 2sa970bl,
Q10-12 = 2sa1209s/sc2911s,
Q13 = ksc2690AY.
cheers,
I was just re-reading some of these posts (Not from work.... 😀 ) and was just looking for clarification on the statement in bold above... not sure what the case has to do with the secondary outputs. did I misunderstand something here?
I was just a little bit concerned about driving the statement II's after reading 125 pages of "the other" Honey Badger thread.
Thanks for any clarification 🙂
We usually get 122vac on a normal outlet, if connected with either a short-length or thick wire. This causes a slight problem with transformers measured at 110v or 115vac.
We do actually have 15a, 20a, 30a, 40a, 244v outlets; however, they're very rare and usually hidden down behind the appliances that require them. Also, they're plug incompatible with each other, very rarely seen and excessively laborious to install. It is a most unfortunate trip though the attic per each effective outlet.
As for the 122vac outlets that are commonplace in the USA, modern spec has them reliant on excessively expensive, yet cheaply made in china breakers with limited lifespan and specs that encourage the installation of cheap thin wiring everywhere but the kitchen. So, if a breaker fails anywhere else, a house goes down in flames, straightaway. This is regarded as a mystery. It seems that, in my country, effective calculator batteries are strictly banned, by law.
Also, on that other topic, so long as there was a bias knob available, the MJL21193/4 may still have considerable charm.
If nothing else, I might have managed to suggest sturdy parts and a soft start circuit?
Cheerio!
Yup, I did...😱
I blame being awake for 47 hours of flying across the country/ & flipping from day-mode to nightshift... This was a bad question, asked due to a poor interpretation of the english language(the only language I speak, LOL)
Please disregard.
Thanks for taking the time to respond. It actually raised a better question for me to ask, but I will wait until I have done some calculations so that I can ask a specific question based on my circumstances!