lm4780
Peter
Thanks for the emails that you have sent so far. I have been reading many of the threads dealing with chip amps and I am finally ready to commit.
I just purchased 4 lm4780 chips and two Switching Power Supply Dual +/-43V 2A for use in a 6 channel chip amp 2 x stereo, 2 x parallel.
I have made a list of parts that I think I still need. I am interested in a premium quality amp; it will be running in a system of a dedicated higher end CD player with variable output (Yamaha CDX 1120), digital 3 way crossover, Peerless HDS component drivers. I am trying to have the best possible sound on a budget.
so here goes the list
2 x 2 lm4780 amplifier pcb:
2 x 8 22k 0.5 w Caddock MK 132 resistors
2 x 4 270R 0.5 w Caddock MK 132 resistors
2 x 4 680R 0.5 w Riken resistors
2 x 2 10k 0.5 w compact film resistors
1 x 4 0.1R 3w Dale LVR3 power resistors (for parallel amps)
2 x 4 1500μF Panasonic FC capacitors
From your experience is this the right combination. Its been a long time since I built an amp.
Is there anything else I should know before I jump into the fire?
Thanks
Dean
Peter
Thanks for the emails that you have sent so far. I have been reading many of the threads dealing with chip amps and I am finally ready to commit.
I just purchased 4 lm4780 chips and two Switching Power Supply Dual +/-43V 2A for use in a 6 channel chip amp 2 x stereo, 2 x parallel.
I have made a list of parts that I think I still need. I am interested in a premium quality amp; it will be running in a system of a dedicated higher end CD player with variable output (Yamaha CDX 1120), digital 3 way crossover, Peerless HDS component drivers. I am trying to have the best possible sound on a budget.
so here goes the list
2 x 2 lm4780 amplifier pcb:
2 x 8 22k 0.5 w Caddock MK 132 resistors
2 x 4 270R 0.5 w Caddock MK 132 resistors
2 x 4 680R 0.5 w Riken resistors
2 x 2 10k 0.5 w compact film resistors
1 x 4 0.1R 3w Dale LVR3 power resistors (for parallel amps)
2 x 4 1500μF Panasonic FC capacitors
From your experience is this the right combination. Its been a long time since I built an amp.
Is there anything else I should know before I jump into the fire?
Thanks
Dean
4 single channels and two parallel channels ( 6 total) will require the following parts:
2 x 2 lm4780 amplifier pcb:
8 x 22k Caddock MK 132 resistors (feedback)
6 x 22k Caddock (parallel setup reguires only one resistor per channel)
2 x 4 220R 0.5 w Caddock MK 132 resistors (they are recommended for parallel setup, but for stereo you don't really need them so 4 pcs only would be fine)
2 x 4 680R 0.5 w Riken resistors
2 x 2 10k 0.5 w compact film resistors
1 x 4 0.1R 3w Dale LVR3 power resistors (for parallel amps)
2 x 4 1500ìF Panasonic FC capacitors
This is the right combination.
2 x 2 lm4780 amplifier pcb:
8 x 22k Caddock MK 132 resistors (feedback)
6 x 22k Caddock (parallel setup reguires only one resistor per channel)
2 x 4 220R 0.5 w Caddock MK 132 resistors (they are recommended for parallel setup, but for stereo you don't really need them so 4 pcs only would be fine)
2 x 4 680R 0.5 w Riken resistors
2 x 2 10k 0.5 w compact film resistors
1 x 4 0.1R 3w Dale LVR3 power resistors (for parallel amps)
2 x 4 1500ìF Panasonic FC capacitors
This is the right combination.
Dougie085 said:
The chassis pictured here: http://audiosector.com/chassis_integrated.shtml is available as a kit at $250. All accessories are extra.
An externally hosted image should be here but it was not working when we last tested it.
Mardone Burl is hard to come across and I can't really offer it with a kit, but most other wood choices are possible.
Attachments
Well I've finally completed the DAC (no more alligator clips !), and is sitting proudly next to my other equipment.
I spent all weekend running music through it, and it does improve substantially once properly warmed up (and it seems to get substantially louder too !).
Sadly, it has revealed some poorly mastered CDs (which probably would have gone unnoticed), and my "transport" is a cheap dvd player, so sometimes the pace feels a little "slow".
Next on the TODO list would be a decent transport (or a player with a decent transport), but as it is now, I'm very satisfied (and so relieved it works ! can you imagine having to desolder a 28 pin SMD IC ? yuk !).
I'll get piccies up soon (no camera atm ...)
I spent all weekend running music through it, and it does improve substantially once properly warmed up (and it seems to get substantially louder too !).
Sadly, it has revealed some poorly mastered CDs (which probably would have gone unnoticed), and my "transport" is a cheap dvd player, so sometimes the pace feels a little "slow".
Next on the TODO list would be a decent transport (or a player with a decent transport), but as it is now, I'm very satisfied (and so relieved it works ! can you imagine having to desolder a 28 pin SMD IC ? yuk !).
I'll get piccies up soon (no camera atm ...)
sobwoofer out
Hi Peter,
some time ago, i build an integrated amp from using your kit (very similar to your integrated amp insides).
it sounds sweet, but my monitors lack some lower frequencies, so i build an active subwoofer (sealed box with Peerless XXLS-10)...
Now i wonder, what would be the best way to design special output for this SW in my gainclone.
How would you do it in your integrated?
Thank you!
Filip
Hi Peter,
some time ago, i build an integrated amp from using your kit (very similar to your integrated amp insides).
it sounds sweet, but my monitors lack some lower frequencies, so i build an active subwoofer (sealed box with Peerless XXLS-10)...
Now i wonder, what would be the best way to design special output for this SW in my gainclone.
How would you do it in your integrated?
Thank you!
Filip
A number of commercial subs take their output from the speaker terminals on the amp. The main speakers get the full bandwidth feed from the amp and the sub rolls in wherever you set the low pass filter. There are some examples of plate amps designed like this on the BK pages.
The argument is that it 'preserves the sonic character of your main speakers and amplifier'. In reality, it makes life a lot easier for those of us with integrated amps. I've been using a Rega sub in this way with my Naim integrated and it works. Ideally, this technique should be used with sealed main speakers so their enclosures roll off the LF, preventing the drivers getting over-driven at low frequencies.
Hope this helps.
The argument is that it 'preserves the sonic character of your main speakers and amplifier'. In reality, it makes life a lot easier for those of us with integrated amps. I've been using a Rega sub in this way with my Naim integrated and it works. Ideally, this technique should be used with sealed main speakers so their enclosures roll off the LF, preventing the drivers getting over-driven at low frequencies.
Hope this helps.
Colin is right. I know REL does this and are very popular. Those of us who have preamps with dual outs can choose between using the RCA out or speaker out. If you do have a preamp, you should try both ways to see what works best in your system and room. However for integrated units, I believe the speaker outs work best. Although with biwired loudspeakers and a pair of subwoofers, things can get crowded back there .
!
Anand
!Anand
Query about grounding LM4780 kit
Hi all,
Ive recently built peters LM4780 kit, and have found the results fantastic!
Everything working great and now considering more tweak.
I am unsure what to do grounding wise when i move to a aluminium chassis (next week, wood at moment).
I have the speaker grounds going to the OG points on the pcb, and my input grounds going to the SG points on the pcb. At the moment (i know i shouldnt do this) the ground off the mains socket is not connected to anything.
In the aluminium case, i am planning to ground this to the case, but i am not sure where to take the ground from on the LM4780 pcb or the power supply pcb.
Im using one power supply pcb and one lm4780 board in stereo.
Thanks
Adam
Hi all,
Ive recently built peters LM4780 kit, and have found the results fantastic!
Everything working great and now considering more tweak.
I am unsure what to do grounding wise when i move to a aluminium chassis (next week, wood at moment).
I have the speaker grounds going to the OG points on the pcb, and my input grounds going to the SG points on the pcb. At the moment (i know i shouldnt do this) the ground off the mains socket is not connected to anything.
In the aluminium case, i am planning to ground this to the case, but i am not sure where to take the ground from on the LM4780 pcb or the power supply pcb.
Im using one power supply pcb and one lm4780 board in stereo.
Thanks
Adam
Here are some useful links concerning my projects, including preferred ground arrangement for GC amps:
Battery charger for DAC:
http://www.diyaudio.com/forums/showthread.php?postid=803967#post803967
DAC polarity fix:
http://www.diyaudio.com/forums/showthread.php?postid=764138#post764138
GC ground arrangement:
http://www.diyaudio.com/forums/showthread.php?postid=787773#post787773
buffer info:
http://www.diyaudio.com/forums/showthread.php?postid=805978#post805978
300pf cap:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=55300&highlight=
Wiring CT transformer:
http://www.diyaudio.com/forums/showthread.php?postid=548382#post548382
Wiring LM3875 kit:
http://www.diyaudio.com/forums/showthread.php?postid=1108820#post1108820
Modyfying dual bridges into single bridges:
http://www.diyaudio.com/forums/showthread.php?postid=1196283#post1196283
Integrated Amp chassis:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=28961&perpage=20&highlight=&pagenumber=34
Oscillator in USB DAC:
http://www.diyaudio.com/forums/showthread.php?postid=1212713#post1212713
Phono stage:
http://www.diyaudio.com/forums/showthread.php?postid=1123520#post1123520
GC upgrades:
http://www.diyaudio.com/forums/showthread.php?postid=1231532#post1231532
NOS DAC:
http://www.diyaudio.com/forums/showthread.php?postid=1170936#post1170936
USB DAC:
http://www.diyaudio.com/forums/showthread.php?postid=1195246#post1195246
Battery charger for DAC:
http://www.diyaudio.com/forums/showthread.php?postid=803967#post803967
DAC polarity fix:
http://www.diyaudio.com/forums/showthread.php?postid=764138#post764138
GC ground arrangement:
http://www.diyaudio.com/forums/showthread.php?postid=787773#post787773
buffer info:
http://www.diyaudio.com/forums/showthread.php?postid=805978#post805978
300pf cap:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=55300&highlight=
Wiring CT transformer:
http://www.diyaudio.com/forums/showthread.php?postid=548382#post548382
Wiring LM3875 kit:
http://www.diyaudio.com/forums/showthread.php?postid=1108820#post1108820
Modyfying dual bridges into single bridges:
http://www.diyaudio.com/forums/showthread.php?postid=1196283#post1196283
Integrated Amp chassis:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=28961&perpage=20&highlight=&pagenumber=34
Oscillator in USB DAC:
http://www.diyaudio.com/forums/showthread.php?postid=1212713#post1212713
Phono stage:
http://www.diyaudio.com/forums/showthread.php?postid=1123520#post1123520
GC upgrades:
http://www.diyaudio.com/forums/showthread.php?postid=1231532#post1231532
NOS DAC:
http://www.diyaudio.com/forums/showthread.php?postid=1170936#post1170936
USB DAC:
http://www.diyaudio.com/forums/showthread.php?postid=1195246#post1195246
CD Pro2 LF
I read from the daisy laser website that they have a new type
of CD Pro2 LF, a lot improvment from the next generation CD
Pro2 M
They guarantee all system like play skip forward and reverse
can do the job best
They told us to wait until the product receive, maybe take
a month
So peter as a great designer ( You are one from the three
of my favourite ) would you like to build another DAC,
use Excellent board, best component (maybe opa 627bp,
BGN, low jitter cristal, best resistor, etc) and the board can
be place it in CD casing or separate
This is MARKETING COMMUNICATION says
Not just product but the customer needed
Oh yes I buy ML38 and i spend near us$1000 to do your mods
+ resistor change in Vishay dale s102
for the polystyrene
Is that right styroflex from Siemens is the best better than lcr?
Just wait for your succes Peter
I read from the daisy laser website that they have a new type
of CD Pro2 LF, a lot improvment from the next generation CD
Pro2 M
They guarantee all system like play skip forward and reverse
can do the job best
They told us to wait until the product receive, maybe take
a month
So peter as a great designer ( You are one from the three
of my favourite ) would you like to build another DAC,
use Excellent board, best component (maybe opa 627bp,
BGN, low jitter cristal, best resistor, etc) and the board can
be place it in CD casing or separate
This is MARKETING COMMUNICATION says
Not just product but the customer needed
Oh yes I buy ML38 and i spend near us$1000 to do your mods
+ resistor change in Vishay dale s102
for the polystyreneIs that right styroflex from Siemens is the best better than lcr?
Just wait for your succes Peter
Another Peter Daniel amp springs to life
Peter,
I am pleased to report that another of your kits has sprung to life and you have another very happy customer.
I really took my time to build your kit, as I wanted to get it right the first time out of the gate, as I am new to the DIY hobby.
I have to report that I am very happy with the results. After reading all the threads and looking at many pictures of the many creative designs I finally committed to a build. I attach pictures of my work in progress. I wanted to have a solid chassis design. I used solid copper blocks for heat sinks and encased the chip amps in aluminum sheet metal. I kept the layout simple to really reduce signal length.
I put the rectifier just on the other side of the heat sink so the path for power would be short, but fully shielded. I sprang for a Plitron transformer with 24v 300va spec, and I am most pleased with the choice. When I turned it on I wondered if it was working, as there was NO sound from the speakers. Until I hit play on the CD and great sound started. It took 2 - 3 hours of burn in before the sound started to open up, and after 100 hrs it still keeps getting better.
In the pictures the attenuator is a temporary shunt with cheap metal film resistors to verify that it would work well with a passive attenuator with 8k impedence. My next step is to build a Lightspeed attenuator based on Silonex optocouplers. I plan to put the couplers very close to the board, as I understand that the attenuator is part of the feedback loop and it just seems right.
Ultimately I will build a Peter Daniel NOS USB DAC and hard wire it to the amp with short signal paths. The whole thins will go into an old case from an integrated amp.
I plan to use solid gold signal wires 3x30 gauge on the + and 24 on the neg in accordance with very interesting posts on audiogon. In the mean time my source is a 20-year-old sony cdp and it sounds unbelievable to my ears.
Speakers are also recycled 20-year-old Boston acoustics that I refoamed and rewired. It was amazing to me what a difference wire can make. I am using all CAT5 Teflon in the speakers and cables and its pretty good. Ultimate plan is for silver on the speakers and gold on the interconnects.
One innovation I am proud of is the use of a CAT5 connector in place of RCA plugs. I did a lot of reading and came to the conclusion that RCAs are just too massive. Some of the expensive and exotic connectors available commercially are merely very low mass in the out of date form factor. The CAT5 connector deals with megahertz data paths and should handle the delicate audio signal. To me it was a great step forward and only $5. I use pins 1 & 6 for left and right positive and 3 & 8 for ground.
I'll post a couple more pics and follow up once it’s all in a case.
Peter, you are a star. It was a pleasure to meet you in person when I picked up the kit. I look forward to seeing you again when I take the next step with the DAC.
Pic is here:
Peter,
I am pleased to report that another of your kits has sprung to life and you have another very happy customer.
I really took my time to build your kit, as I wanted to get it right the first time out of the gate, as I am new to the DIY hobby.
I have to report that I am very happy with the results. After reading all the threads and looking at many pictures of the many creative designs I finally committed to a build. I attach pictures of my work in progress. I wanted to have a solid chassis design. I used solid copper blocks for heat sinks and encased the chip amps in aluminum sheet metal. I kept the layout simple to really reduce signal length.
I put the rectifier just on the other side of the heat sink so the path for power would be short, but fully shielded. I sprang for a Plitron transformer with 24v 300va spec, and I am most pleased with the choice. When I turned it on I wondered if it was working, as there was NO sound from the speakers. Until I hit play on the CD and great sound started. It took 2 - 3 hours of burn in before the sound started to open up, and after 100 hrs it still keeps getting better.
In the pictures the attenuator is a temporary shunt with cheap metal film resistors to verify that it would work well with a passive attenuator with 8k impedence. My next step is to build a Lightspeed attenuator based on Silonex optocouplers. I plan to put the couplers very close to the board, as I understand that the attenuator is part of the feedback loop and it just seems right.
Ultimately I will build a Peter Daniel NOS USB DAC and hard wire it to the amp with short signal paths. The whole thins will go into an old case from an integrated amp.
I plan to use solid gold signal wires 3x30 gauge on the + and 24 on the neg in accordance with very interesting posts on audiogon. In the mean time my source is a 20-year-old sony cdp and it sounds unbelievable to my ears.
Speakers are also recycled 20-year-old Boston acoustics that I refoamed and rewired. It was amazing to me what a difference wire can make. I am using all CAT5 Teflon in the speakers and cables and its pretty good. Ultimate plan is for silver on the speakers and gold on the interconnects.
One innovation I am proud of is the use of a CAT5 connector in place of RCA plugs. I did a lot of reading and came to the conclusion that RCAs are just too massive. Some of the expensive and exotic connectors available commercially are merely very low mass in the out of date form factor. The CAT5 connector deals with megahertz data paths and should handle the delicate audio signal. To me it was a great step forward and only $5. I use pins 1 & 6 for left and right positive and 3 & 8 for ground.
I'll post a couple more pics and follow up once it’s all in a case.
Peter, you are a star. It was a pleasure to meet you in person when I picked up the kit. I look forward to seeing you again when I take the next step with the DAC.
Pic is here:
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