Re: Soldering little bugs
Oh I don't know about the Scotch, depends on whether it will steady your hand more than it blurs your vision.
I actually manage the purchasing department in a large Electronics manufacturer. We have 3 SMT lines, Genisis, GSM and Panasonic. We use Loctite SMD Adhesive to hold parts in place, but it needs to be ordered over night delivery as it must remain refridgerated until use. If you have a lot of parts to put down the Toaster oven method works with a little practise, but for one offs I still prefer a steady hand and a bit of solder.
Anthony
dcbingaman said:
udailey said:
Oh I don't know about the Scotch, depends on whether it will steady your hand more than it blurs your vision.
I actually manage the purchasing department in a large Electronics manufacturer. We have 3 SMT lines, Genisis, GSM and Panasonic. We use Loctite SMD Adhesive to hold parts in place, but it needs to be ordered over night delivery as it must remain refridgerated until use. If you have a lot of parts to put down the Toaster oven method works with a little practise, but for one offs I still prefer a steady hand and a bit of solder.
Anthony
tooling adhesives for SOIC's
I like the adhesive idea - I was thinking potting compound might work OK also, but I might try either super-glue or "Gorilla Glue" contact cement first. You guys have convinced me that this is doable.
And, Anthony, in my case, the hands steady before the vision goes with good Scotch....but that is only after one. After three, all bets are off. According to my wife, even my other appendages are of little use. I say its age !!
I like the adhesive idea - I was thinking potting compound might work OK also, but I might try either super-glue or "Gorilla Glue" contact cement first. You guys have convinced me that this is doable.
And, Anthony, in my case, the hands steady before the vision goes with good Scotch....but that is only after one. After three, all bets are off. According to my wife, even my other appendages are of little use. I say its age !!
Re: tooling adhesives for SOIC's
My wife is the Scotch aficionado, I am a beer snob, Spitfire Ale, Old Speckeled Hen..... anyway remember the point of the glue is only to tack while you are soldering. Most of the product you mention will ensure a permanent bond and heartache if you have to rework.
Regards
Anthony
dcbingaman said:
My wife is the Scotch aficionado, I am a beer snob, Spitfire Ale, Old Speckeled Hen..... anyway remember the point of the glue is only to tack while you are soldering. Most of the product you mention will ensure a permanent bond and heartache if you have to rework.
Regards
Anthony
Volume....
I paid close attention to the plus/minus when I assembled the B1 but that seems the easiest place to start. There is no "star" ground to the chasis as the board is on nylon standoffs. The RCA input and output "G"rounds are all insulated from the chasis also. All wired connections to the RCA's, Pots, and Toggles are single conductor wire insulated. Wire insulation on all wires is not connected. I do notice that there is distortion after the volume is turned above 50% although volume is extremely low.
I don't understand "backkwards" FET's ???
-BP
I paid close attention to the plus/minus when I assembled the B1 but that seems the easiest place to start. There is no "star" ground to the chasis as the board is on nylon standoffs. The RCA input and output "G"rounds are all insulated from the chasis also. All wired connections to the RCA's, Pots, and Toggles are single conductor wire insulated. Wire insulation on all wires is not connected. I do notice that there is distortion after the volume is turned above 50% although volume is extremely low.
I don't understand "backkwards" FET's ???
-BP
Re: balanced setup.
dunno .....
maybe I did ...... maybe not ;
use one stereo B1 per channel ....... one channel of B1 for pos. leg , other channel of B1 for neg. leg
look in PSM LS thread to see how 4 separated buffers are used for balanced operation .
peace of cake .
Tea-Bag said:Didn't someone earlier do a post about using the traditional B1 schematic in balanced operation by using the out's on these tied to a 1 and 2 of XLR? I can't seem to find such a post. Was I dreaming it?
dunno .....
maybe I did ...... maybe not ;
use one stereo B1 per channel ....... one channel of B1 for pos. leg , other channel of B1 for neg. leg
look in PSM LS thread to see how 4 separated buffers are used for balanced operation .
peace of cake .
Some first reflections on B1 ... Remark: I am talking here about "original" Pass B1 design.
I had some thoughts on power supply. The question was how much to invest in it: whether to go with good shunt reg or to use something simpler or even to go with something very simple - that was the first question ..
So together with a friend of mine I put simple power supply of 18 V DC: transformer -> elco -> standard LM317 Reg -> B1. On the input of B1 I have Nichicon Elco of 15 mF, 25V. On the other side I put together simple battery supply made of lot of AA Alcaline 1,5V batteries. The voltage was the same: 18V DC. I installed a switch so that I can easily switch from one supply to another. And I couldn't really hear any difference in sound reproduction.
Then I increased the battery voltage to 23V. And again I couldn't really hear any difference. I know that THD is lower when the voltage is higher but in real life I cannot make difference ... at least not on the system where I was testing (solid middle of the class HiFi system).
These are some experiences that might help somebody. My personal conclusion is that B1 is made as a simple buffer and that it should be kept simple. Maybe some experiments with input and output caps would be interesting (for example with Auricaps) but power supply should be done correctly but there is no real need for some extravaganza ...
http://i277.photobucket.com/albums/kk50/dejan2604/PassB1.jpg
I had some thoughts on power supply. The question was how much to invest in it: whether to go with good shunt reg or to use something simpler or even to go with something very simple - that was the first question ..
So together with a friend of mine I put simple power supply of 18 V DC: transformer -> elco -> standard LM317 Reg -> B1. On the input of B1 I have Nichicon Elco of 15 mF, 25V. On the other side I put together simple battery supply made of lot of AA Alcaline 1,5V batteries. The voltage was the same: 18V DC. I installed a switch so that I can easily switch from one supply to another. And I couldn't really hear any difference in sound reproduction.
Then I increased the battery voltage to 23V. And again I couldn't really hear any difference. I know that THD is lower when the voltage is higher but in real life I cannot make difference ... at least not on the system where I was testing (solid middle of the class HiFi system).
These are some experiences that might help somebody. My personal conclusion is that B1 is made as a simple buffer and that it should be kept simple. Maybe some experiments with input and output caps would be interesting (for example with Auricaps) but power supply should be done correctly but there is no real need for some extravaganza ...
http://i277.photobucket.com/albums/kk50/dejan2604/PassB1.jpg
I am still wondering why paying for quality capacitors when B1 can safely be made without input and output coupling if using symmetric (+/-) supplies. I still use it like that for months now, and the offset is practically null. And no cap always sounds better than any cap.
If I was using B1 for main system, I would use +/- 10V Mosfet shunts, and minimal applicable Shinkoh input and output series resistors (after test in given system for square waves). That is how making it for top performance.
If I was using B1 for main system, I would use +/- 10V Mosfet shunts, and minimal applicable Shinkoh input and output series resistors (after test in given system for square waves). That is how making it for top performance.
Hi,
Its not cold when capacitor-less, it sounds neutral but soft. Maybe a bit ''gray''. The input and output resistors values and quality as well as the pot seal the tone. +/- 10V is the sweet spot I found for most relaxed sonics.
In tubes the capacitors are more to see because of the vacuum device one way nature, economic and bulk cost of extra PSUs etc. Every time we use better capacitors, they show there too. So it would be better if they weren't needed.
Its not cold when capacitor-less, it sounds neutral but soft. Maybe a bit ''gray''. The input and output resistors values and quality as well as the pot seal the tone. +/- 10V is the sweet spot I found for most relaxed sonics.
In tubes the capacitors are more to see because of the vacuum device one way nature, economic and bulk cost of extra PSUs etc. Every time we use better capacitors, they show there too. So it would be better if they weren't needed.