How do you think you will adapt the metal package? Are you planning in using a browndog adapter?
An adapter is neither needed nor desirable. The leads of a TO-99 package can be formed to fit the eight pin DIP pattern. Back when TO-99's were more common, some semiconductor manufacturers offered them with pre-formed leads to fit a DIP pattern on the PC board.
Regi,
With the metal package you can just stick their legs in the DIP8 socket and try it out. No need for Brown Dogs but if you decide to keep it a Brown Dog adapter might be nice.
AndrewT, we are using the gerbers from Twisted Pear, the exact same gerbers, unmodified and sent to me by Russ. Some PRP are a little bigger than the Dales, etc that it was designed for and the board was not designed for a cap as big as a Black Gate. With the care that you read each thread I am suprised that the fact that a cap or resistor might need extra care to get it to fit is news to you. Its been discussed every few pages on this thread as well as the build thread where Dario and Tom experimented with different caps and resistors.
Uriah
With the metal package you can just stick their legs in the DIP8 socket and try it out. No need for Brown Dogs but if you decide to keep it a Brown Dog adapter might be nice.
AndrewT, we are using the gerbers from Twisted Pear, the exact same gerbers, unmodified and sent to me by Russ. Some PRP are a little bigger than the Dales, etc that it was designed for and the board was not designed for a cap as big as a Black Gate. With the care that you read each thread I am suprised that the fact that a cap or resistor might need extra care to get it to fit is news to you. Its been discussed every few pages on this thread as well as the build thread where Dario and Tom experimented with different caps and resistors.
Uriah
AFIK this is not possible, Uriah has already the boards at home. Am I wrong? Can we see a picture of the bunch of boards? 
Uriah,
I have some questions:
-Why the R14 1W res. is like 4 times bigger than R1 and R4, which are 1W too? R1 and R4 look a bit too small compared with other MyRefs builds.
-Why R15 and R16 doesn't fit, being standard 250mW parts?
-You have put the tantalum one only in R12, not in R10 too. Why this PRP/tantalum mixing?
-Do the little ones diodes fit on the board? they look like being lifted...
-R11 is not a PRP, is that a tantalum one?
-C21 seems to have a weird for I have never seen before. Or maybe is because of the angle of the picture.
-Are you sure we are not able to fit the Blackgate on top of the board? It seems to be enough clearance if you fit it there if you put the input cap C13 out of the board.
-Can we see pictures of the output resistor heatsink? It seems that there are enought clearance, it should be quite big...
-I can see that you finally went with the uninsulated LM3886 version. Lucky me for having some insulated versions around home.
BTW, those obbligatos look georgeous and sexy!!!
Sorry for my curiosity, maybe I have too many questions... I am glad you are a very comprehensive guy, Uriah.
PD: How are you doing with your move? Are the ants still walking around your house? hehehe
Uriah,
I have some questions:
-Why the R14 1W res. is like 4 times bigger than R1 and R4, which are 1W too? R1 and R4 look a bit too small compared with other MyRefs builds.
-Why R15 and R16 doesn't fit, being standard 250mW parts?
-You have put the tantalum one only in R12, not in R10 too. Why this PRP/tantalum mixing?
-Do the little ones diodes fit on the board? they look like being lifted...
-R11 is not a PRP, is that a tantalum one?
-C21 seems to have a weird for I have never seen before. Or maybe is because of the angle of the picture.
-Are you sure we are not able to fit the Blackgate on top of the board? It seems to be enough clearance if you fit it there if you put the input cap C13 out of the board.
-Can we see pictures of the output resistor heatsink? It seems that there are enought clearance, it should be quite big...
-I can see that you finally went with the uninsulated LM3886 version. Lucky me for having some insulated versions around home.
BTW, those obbligatos look georgeous and sexy!!!
Sorry for my curiosity, maybe I have too many questions...
I am glad you are a very comprehensive guy, Uriah.PD: How are you doing with your move? Are the ants still walking around your house? hehehe
AFIK this is not possible, Uriah has already the boards at home. Am I wrong? Can we see a picture of the bunch of boards?
Uriah,
I have some questions:
-Why the R14 1W res. is like 4 times bigger than R1 and R4, which are 1W too? R1 and R4 look a bit too small compared with other MyRefs builds.
-Why R15 and R16 doesn't fit, being standard 250mW parts?
-You have put the tantalum one only in R12, not in R10 too. Why this PRP/tantalum mixing?
-Do the little ones diodes fit on the board? they look like being lifted...
-R11 is not a PRP, is that a tantalum one?
-C21 seems to have a weird shape that I have never seen before. Or maybe is because of the angle of the picture.
-Are you sure we are not able to fit the Blackgate on top of the board? It seems to be enough clearance if you put the input cap C13 (obbligato) out of the board.
-Can we see pictures of the output resistor heatsink? It seems that there is enought clearance. It should be quite big for not fitting
-I can see that you finally went with the uninsulated LM3886 version. Lucky me for having some insulated versions around home. I dislike the possibility of having any kind of short because of my incompetence.
Sorry for my curiosity, maybe I have too many questions... I am glad you are a very comprehensive guy, Uriah.
BTW, those obbligatos look georgeous and sexy!!!
PD: How are you doing with your move? Are the ants still walking around your house?
Uriah,
I have some questions:
-Why the R14 1W res. is like 4 times bigger than R1 and R4, which are 1W too? R1 and R4 look a bit too small compared with other MyRefs builds.
-Why R15 and R16 doesn't fit, being standard 250mW parts?
-You have put the tantalum one only in R12, not in R10 too. Why this PRP/tantalum mixing?
-Do the little ones diodes fit on the board? they look like being lifted...
-R11 is not a PRP, is that a tantalum one?
-C21 seems to have a weird shape that I have never seen before. Or maybe is because of the angle of the picture.
-Are you sure we are not able to fit the Blackgate on top of the board? It seems to be enough clearance if you put the input cap C13 (obbligato) out of the board.
-Can we see pictures of the output resistor heatsink? It seems that there is enought clearance. It should be quite big for not fitting
-I can see that you finally went with the uninsulated LM3886 version. Lucky me for having some insulated versions around home. I dislike the possibility of having any kind of short because of my incompetence.
Sorry for my curiosity, maybe I have too many questions...
I am glad you are a very comprehensive guy, Uriah.BTW, those obbligatos look georgeous and sexy!!!
PD: How are you doing with your move? Are the ants still walking around your house?
AFIK this is not possible, Uriah has already the boards at home. Am I wrong? Can we see a picture of the bunch of boards?
Uriah,
I have some questions:
-Why the R14 1W res. is like 4 times bigger than R1 and R4, which are 1W too? R1 and R4 look a bit too small compared with other MyRefs builds.
-Why R15 and R16 doesn't fit, being standard 250mW parts?
-You have put the tantalum one only in R12, not in R10 too. Why this PRP/tantalum mixing?
-Do the little ones diodes fit on the board? they look like being lifted...
-R11 is not a PRP, is that a tantalum one?
-C21 seems to have a weird shape that I have never seen before. Or maybe is because of the angle of the picture.
-Are you sure we are not able to fit the Blackgate on top of the board? It seems to be enough clearance if you put the input cap C13 (obbligato) out of the board.
-Can we see pictures of the output resistor heatsink? It seems that there is enought clearance. It should be quite big for not fitting
-I can see that you finally went with the uninsulated LM3886 version. Lucky me for having some insulated versions around home. I dislike the possibility of having any kind of short because of my incompetence.
Sorry for my curiosity, maybe I have too many questions...
BTW, those obbligatos look georgeous and sexy!!!
PD: How are you doing with your move? Are the ants still walking around your house?
Check out Panasonic 1/4W vs Dale RN 1/4W. Just because the same wattage doesnt mean same size.
R1 and R4 are actually 2W.
R14 is probably bigger because it is 470R rather than 33k or something else like that.
I put a tantalum in because I want to try it. At $4 each they are not in the kits.
You could fit the Black Gate on top if you put others on the bottom. Its the circumference that keeps if from working on top.
C21 is a box. Square on all sides.
Yes, I did go uninsulated. It was cheaper than insulated and otherwise the same chip.
There is a pic of the sink here
AAVID THERMALLOY|551002B00000G|Heat Sink | Newark.com
Now let me trot off to get a pic of the boards.....
Uriah
R11 looks like the Xicon that came with the original kits. No big deal.
R1 and R4 should be TWO watt resistors, and they are tiny compared to those in the original kits. Mine work fine. Doubt that quality here means much sonically, but tighter tolerance is probably a good thing.
Nothing wrong, and maybe something right, about those tiny diodes being lifted off the board a little bit.
Uriah, that surely is a beautiful picture!
Okay, so a couple glitches, but nothing that imperils the successful completion of these amps. A few components sticking up in the air doesn't cause any harm, and, unless you are anal retentive, after you hear these things you'll forget all about their cobbled appearance.
The Blackgate will fit on top of the board, but the leads must be bent slightly into an "L" to get it far enough off to the side where the input cap normally goes. Then you must put C21 under the board, but it is smaller and allows for reasonably short standoffs. There is no way both will fit on top. That's how I did mine. I also put a small piece of foam rubber underneath it so it wouldn't shake around. It cannot be put firmly against the PCB.
Russ did a great job of designing these boards to be compact and for parts he wanted to use, and probably never imagined it would serve as the basis for a hot rodded kit. One thing for certain: this amp is easy to build, but in this configuration it will require some tinkering. Everything can be made to fit, and they will work well and sound beautiful.
Peace,
Tom E
R1 and R4 should be TWO watt resistors, and they are tiny compared to those in the original kits. Mine work fine. Doubt that quality here means much sonically, but tighter tolerance is probably a good thing.
Nothing wrong, and maybe something right, about those tiny diodes being lifted off the board a little bit.
Uriah, that surely is a beautiful picture!
Okay, so a couple glitches, but nothing that imperils the successful completion of these amps. A few components sticking up in the air doesn't cause any harm, and, unless you are anal retentive, after you hear these things you'll forget all about their cobbled appearance.
The Blackgate will fit on top of the board, but the leads must be bent slightly into an "L" to get it far enough off to the side where the input cap normally goes. Then you must put C21 under the board, but it is smaller and allows for reasonably short standoffs. There is no way both will fit on top. That's how I did mine. I also put a small piece of foam rubber underneath it so it wouldn't shake around. It cannot be put firmly against the PCB.
Russ did a great job of designing these boards to be compact and for parts he wanted to use, and probably never imagined it would serve as the basis for a hot rodded kit. One thing for certain: this amp is easy to build, but in this configuration it will require some tinkering. Everything can be made to fit, and they will work well and sound beautiful.
Peace,
Tom E
Tom,
Thanks for the help.
R1 and R4 are 2 watt Dales. Smaller than others I have used but 2 watt nonetheless. Not low quality by any means.
R11 is a KOA Speer. I like KOA personally. So I was bummed that PRP did not come in 1R but glad to see that at least the only one I could find was KOA.
Uriah
Wow, Dario, that's a very comprehensive document. However, I see one thing I think is not right, but it's a minor detail. I would like Uriah to confirm what is the rating of the Caddock resistor in the kit. I use a 60 watt, which may be overkill, but it costs no more than a smaller one. These power resistors are derated very steeply according to case temp, and I didn't want to risk using one with too low rating. Mauro was not in favor of using such resistor types because of possible impulse and power dissipation issues. I worked around that by using a part with a higher rating and a heatsink, although it is only modest size.
Dario, your chart shows 5 watt, which is almost certainly too small. The Mouser part number for the one I used is 684-MP2060-0.5, and that matches what is on your chart.
Peace,
Tom E
Dario, your chart shows 5 watt, which is almost certainly too small. The Mouser part number for the one I used is 684-MP2060-0.5, and that matches what is on your chart.
Peace,
Tom E
PCB Dimensions
Hi Folks,
I know the board dimensions are on one of the posts a ways back I searched for ten minutes and didn't find them.
I found the pdf of the board you posted here Uriah
http://www.diyaudio.com/forums/chip-amps/54571-my-audiophile-lm3886-approach-299.html#post1666231
If I view this at 100% am I seeing actual size (assuming my computer knows what size my monitor is, which it does).
Also with the Blackgate mounted underneath and those big caps on top can you give a ball park measurement for standoffs, and head clearance.
I might start work on a case.... Looking at an old cast iron dutch oven as an option. I like to use unusual found objects or bake-ware where possible just because I'm a cheapskate!
Thanks
Bill
Hi Folks,
I know the board dimensions are on one of the posts a ways back I searched for ten minutes and didn't find them.
I found the pdf of the board you posted here Uriah
http://www.diyaudio.com/forums/chip-amps/54571-my-audiophile-lm3886-approach-299.html#post1666231
If I view this at 100% am I seeing actual size (assuming my computer knows what size my monitor is, which it does).
Also with the Blackgate mounted underneath and those big caps on top can you give a ball park measurement for standoffs, and head clearance.
I might start work on a case.... Looking at an old cast iron dutch oven as an option. I like to use unusual found objects or bake-ware where possible just because I'm a cheapskate!
Thanks
Bill
Thanks Tom,
The 'Description' field contains (mostly) the specifications of Mauro's original BOM so it's normal that sometimes it differs from real parts.
For the power resitor R3 is so speficified as a 5W cement resistor but the part suggested is the 60W Caddock...
Another example is C32 where a C0G type cap is specified but the suggested part is a Wima FKP2.
I've found on Mauro's website an interesting document regarding a Rev A revision of his non-pubblic MyRef Evolution amp.
The MyRef Evolution differs mainly from the original MyRef we're going to build in these key points:
- Rectification diodes are discrete soft recovery (we're using the same diodes)
- the LM318 PSU is a shunt regulator (we could do the same)
- the feedback net has a DC servo that eliminates C9
- it support bridging of two LM3886 on board
- it uses SMD parts
Could be an inspiration for further (and deeper) mods...
I am thinking in the possibility of suplying the LM318 with an spare board from a DCB1 Salas preamp. It will serve by not installing the preamp section, only the regulator section.
It is a REALLY nice high-end shunt regulator suplying +/-10v, but voltage can be easily modded by adding or removing leds. Just hooking up + and - to the right pads, and ground to ground.
As an added bonus, just adding some components and transistors to the board will give you a top high end preamp. Add an LDR volume control from the kit, and I cannot think in having a better integrated amp.
It is a REALLY nice high-end shunt regulator suplying +/-10v, but voltage can be easily modded by adding or removing leds. Just hooking up + and - to the right pads, and ground to ground.
As an added bonus, just adding some components and transistors to the board will give you a top high end preamp. Add an LDR volume control from the kit, and I cannot think in having a better integrated amp.
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