Very nice
Why not just turn the whole chassis over?
Do you have inductor on output, if so what rating and why?
What is your power supply?
Im interested in those boards. Can you post a URL giving more information on these Redshift187 boards please.
Thanks
@DynacoDave: Yes that one is off the shelf, it's from fisher elektronic, model EUG13.
@mikesnowdon: Well I prefer the look this way, if there will be need for colling I will turn it upside down. I have inductor on the output, I don't know the rating because it's from an old Sherwood amp. I put it there just to slightly soften the sound, but I must say that I haven't noticed any difference with it or without it.
http://www.diyaudio.com/forums/chip-amps/133114-lm3886-servo-design.html
@mikesnowdon: Well I prefer the look this way, if there will be need for colling I will turn it upside down. I have inductor on the output, I don't know the rating because it's from an old Sherwood amp. I put it there just to slightly soften the sound, but I must say that I haven't noticed any difference with it or without it.
http://www.diyaudio.com/forums/chip-amps/133114-lm3886-servo-design.html
Ahh ok.
More generally inductors are put in the output to keep the amp stable with differing cable lengths and/or properties. Purists will shun the idea of en extra component in the signal path but a good air core inductor shouldn't have any negative effects on the sound quality. Its a great build. I really like it
Thanks or the link
Arjen MKIII TA2020 fits nicely in a cigar box.
I think my first post was killed by the snow storm. Well anyway.
This is a Arjen Helder MKIII TA2020 board and power supply that I have been working on today while the snow is comming down. I have a tube buffer amp that goes with it but I haven't built it out yet. I can't decide if I should just put it in the signal path between the pot and the selector or build it as a stand alone component between the amp and a cd player? I put an extra 12v plug on the power supply just in case I do the second.
Pardon the Cuban cigar box that I found at Goodwill (and I'm sticking to this story). The box is nice in that it says 25 Robustos on the side which is the rated watts for this amp approx.
I am starting to like the sound of this amp now that the shrillness of the new caps are fading. I almost don't miss my regular amp, ST-70 with VTA mod.
I think I will eventually change out the output caps and could use a suggestion for that (although I think these stock red caps are really not that bad).
For power supply housing I just used an old projcct box from a yard sale box full of 1940s' toy train table parts. Notice the glass lights and switches. The copper accents are from the back plate of an Akai M-8 reel to reel that was gutted for a mono amp project last year.
Happy Holidays and enjoy the snow.
Ashevillebob
I think my first post was killed by the snow storm. Well anyway.
This is a Arjen Helder MKIII TA2020 board and power supply that I have been working on today while the snow is comming down. I have a tube buffer amp that goes with it but I haven't built it out yet. I can't decide if I should just put it in the signal path between the pot and the selector or build it as a stand alone component between the amp and a cd player? I put an extra 12v plug on the power supply just in case I do the second.
Pardon the Cuban cigar box that I found at Goodwill (and I'm sticking to this story). The box is nice in that it says 25 Robustos on the side which is the rated watts for this amp approx.
I am starting to like the sound of this amp now that the shrillness of the new caps are fading. I almost don't miss my regular amp, ST-70 with VTA mod.
I think I will eventually change out the output caps and could use a suggestion for that (although I think these stock red caps are really not that bad).
For power supply housing I just used an old projcct box from a yard sale box full of 1940s' toy train table parts. Notice the glass lights and switches. The copper accents are from the back plate of an Akai M-8 reel to reel that was gutted for a mono amp project last year.
Happy Holidays and enjoy the snow.
Ashevillebob
Attachments
First homemade aluminum box
This was a fun project, especially the aluminum work. Amp sounds great and I'm pleased overall. I'd like to pass along a word of thanks to the very fine folks on this forum for their generous spirit and technical expertise. Merry Xmas all!
This was a fun project, especially the aluminum work. Amp sounds great and I'm pleased overall. I'd like to pass along a word of thanks to the very fine folks on this forum for their generous spirit and technical expertise. Merry Xmas all!
Attachments
String driver.
Here is a board which Supplies 6 Chipsamp.com LM1875 amplifiers and routs the in and out to headers.
It is not actually for an audio amplifier but for a experimental musical instrument
Neutron Physical Guitar Synth.
I expect i may blow a chipamp now and again while experimenting thats why i made them so they can be easilly swapped out.
All the amps are tested, and the board is tested for shorts and continuity, i just have to test the new PSU part, drill the heatsink and bolt on the chips. and then test them all together.
The amps are using the ground strap on the board, and are silent individually, but there is a star ground on the board in case that becomes a problem when everything is working together.
Here is a board which Supplies 6 Chipsamp.com LM1875 amplifiers and routs the in and out to headers.
It is not actually for an audio amplifier but for a experimental musical instrument
Neutron Physical Guitar Synth.
I expect i may blow a chipamp now and again while experimenting thats why i made them so they can be easilly swapped out.
All the amps are tested, and the board is tested for shorts and continuity, i just have to test the new PSU part, drill the heatsink and bolt on the chips. and then test them all together.
The amps are using the ground strap on the board, and are silent individually, but there is a star ground on the board in case that becomes a problem when everything is working together.
Well done Neutron7 !!!!
I'm planning to make a Parallel bridged amp using 3 + 3 LM1875 to reach upto 100W, using dual PSU 22Vcc ---> 16VAC x 6A each and 47000 uF each rail.
But I'll add them a servo circuit to control vcc offset to be "as zero as possibe" LOL..
Well it will take me a while due to my low budget, but i want to do this.
I will use it for a bass amp, so i'll add it a nice preamp too... and nice pair of 10" 98dB 8 ohms each to get 4 ohms parallel... or i'll look for a nice 4 ohms 12".... I'm building my PCBs as well, I've found great PCB manufacturers here in Argentina... so....
Well all advices, comments, etc are wellcome, finally i've found a challenge to do
Good luck with your project and happy new year everyone
I'm planning to make a Parallel bridged amp using 3 + 3 LM1875 to reach upto 100W, using dual PSU 22Vcc ---> 16VAC x 6A each and 47000 uF each rail.
But I'll add them a servo circuit to control vcc offset to be "as zero as possibe" LOL..
Well it will take me a while due to my low budget, but i want to do this.
I will use it for a bass amp, so i'll add it a nice preamp too... and nice pair of 10" 98dB 8 ohms each to get 4 ohms parallel... or i'll look for a nice 4 ohms 12".... I'm building my PCBs as well, I've found great PCB manufacturers here in Argentina... so....
Well all advices, comments, etc are wellcome, finally i've found a challenge to do
Good luck with your project and happy new year everyone
You could just as well use 2xLM3886 or 2xTDA7293 in parallel fed from a 2x24 V transformer to achieve the same result with less effort. In theory even a single TDA7293 should be able to deliver 100 W into 4 Ohm, but it will probably run into heatsinking problems.
When you write bass amp, you mean bass guitar amp, not subwoofer amp, don't you? For a bass guitar amp, you will be happier with a tube amplifier. If you find a 10" 8 Ohm woofer that can do 98 dB, do post. Many people will be interested. Until then go for a 1x15" or 2x12" speaker and don't worry too much about the amplifier power. A 100 W amplifier only appears double as loud as a 10 W amplifier.
For subwoofers a solid state or class D amplifier will be a better choice.
When you write bass amp, you mean bass guitar amp, not subwoofer amp, don't you? For a bass guitar amp, you will be happier with a tube amplifier. If you find a 10" 8 Ohm woofer that can do 98 dB, do post. Many people will be interested. Until then go for a 1x15" or 2x12" speaker and don't worry too much about the amplifier power. A 100 W amplifier only appears double as loud as a 10 W amplifier.
For subwoofers a solid state or class D amplifier will be a better choice.
Hi pacificblue, thank you so much for your advise.
, anyway I've never done a tube amp before, i'd like to try that too, thanks for the advise.
Yeas I was thinking maybe to do so, to use 2x LM3886, I already have the LM1875, but I can buy a couple of LM3886 and give it a try.
Yeas i meant bass guitar amp, i'm sorry i thought i worte that way
, anyway I've never done a tube amp before, i'd like to try that too, thanks for the advise.Mmhh, I hope the fabricant i've found don't lie to me about those dBs shown in datasheets
Mmhh, thanks for that too... I'm thinking about that too, I think if i want to test how a parallel bridged amp would work, i could try a 2 + 2 LM1875 without even care about the Watts, don't you think? Well, i can get lots of ideas here, there are so many great designs and advices, thanks a lot, I'll post photos soon (i hope).