I am happy to share with you my creation, published in an Italian DIY magazine called "Costruire Hi-Fi"
It 'a headphone amplifier that uses two operational amplifiers opa2132.
Board size 60mm X 100mm with on board power supply.
It 'a headphone amplifier that uses two operational amplifiers opa2132.
Board size 60mm X 100mm with on board power supply.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Hello.
It is not a kit. I was inspired by the figure of 9 in the datasheet OPA604. The input stage has been carefully studied. The OPA2132 operational amplifier has a bandwidth of 8 MHz, the bandwidth on my circuit is 3.5 Hz-60 kHz.
schematic of single channel
An externally hosted image should be here but it was not working when we last tested it.
The power supply scheme is very simple. consists of the positive regulator 7812 and its complementary negative 7912. The power transformer is the type mounted on PCB 12 +12 V 3VA EI30 series. The bridge rectifier, KBL06 is mounted near the transformer, so it is not visible in the figure.
There are two leds for control -12 and +12V
There are two leds for control -12 and +12V
An externally hosted image should be here but it was not working when we last tested it.
nice board. Perhaps a great "add on"...
to a Tripath based amp for headphones. Thinking others must want something similar to the Nuforce Icon integrated amp as a project. Now just need a passive RIAA stage, and suitable drivers (stereo microphone amp?) and a full featured integrated with hp amp/RIAA amp/and multiple inputs would be in the making, hey Pano?
Thanks for the troubleshooting on the amp6Basic, Pano. checked all the solder, and used a Dremmel tool w/jeweler bit to isolate any issues with any pads. Gotta clean it up, test, and then paint over the board with some nail polish (lacquer) to seal it all up. I think the "sneaky" version would be the one to use for a complete project. May have to get a larger enclosure...
Is this hp amp circuit board available?
to a Tripath based amp for headphones. Thinking others must want something similar to the Nuforce Icon integrated amp as a project. Now just need a passive RIAA stage, and suitable drivers (stereo microphone amp?) and a full featured integrated with hp amp/RIAA amp/and multiple inputs would be in the making, hey Pano?
Thanks for the troubleshooting on the amp6Basic, Pano. checked all the solder, and used a Dremmel tool w/jeweler bit to isolate any issues with any pads. Gotta clean it up, test, and then paint over the board with some nail polish (lacquer) to seal it all up. I think the "sneaky" version would be the one to use for a complete project. May have to get a larger enclosure...
Is this hp amp circuit board available?
I don't understand...
aris69,
it is I who owes an apology to you. Pano had helped me solve a problem I was having with a 41Hz amp6Basic. I had not meant to hijack your thread.
When I saw this thread, I thought your headphone amplifier, along with a Tripath amp (a kit, DIY from scratch, inexpensive eBay class "D" or "T" that could be improved), a few inputs with suitable switching, a passive RIAA phono preamplifier, a selectable gain microphone "head amp" to allow the use of MM or MC cartridges, and the largest possible suitable power supply could result in the creation of a (one of the very few) full featured digital integrated amplifier It would only be missing tone controls and a balance control, but most who have them should defeat those anyway.
Again, I am sorry if I seemed to hijack your thread, aris69.
aris69,
it is I who owes an apology to you. Pano had helped me solve a problem I was having with a 41Hz amp6Basic. I had not meant to hijack your thread.
When I saw this thread, I thought your headphone amplifier, along with a Tripath amp (a kit, DIY from scratch, inexpensive eBay class "D" or "T" that could be improved), a few inputs with suitable switching, a passive RIAA phono preamplifier, a selectable gain microphone "head amp" to allow the use of MM or MC cartridges, and the largest possible suitable power supply could result in the creation of a (one of the very few) full featured digital integrated amplifier It would only be missing tone controls and a balance control, but most who have them should defeat those anyway.
Again, I am sorry if I seemed to hijack your thread, aris69.
10k pot...
I'm no designer, so just wishful thinking. But if the Tripath amp could be muted or shut down with a switch (Pano, help me out here...use a momentary switch in place of the sleep jumper)?
The RIAA amp can be just passive, with the output connected to the microphone "head amp". 2 gain settings could allow for MM and MC connection. I guess I could make a quick sketch to show what I mean.
I'm no designer, so just wishful thinking. But if the Tripath amp could be muted or shut down with a switch (Pano, help me out here...use a momentary switch in place of the sleep jumper)?
The RIAA amp can be just passive, with the output connected to the microphone "head amp". 2 gain settings could allow for MM and MC connection. I guess I could make a quick sketch to show what I mean.
I like your project very much and I'm planning to try it soon.
I'm waiting for the issue of CHF that I ordered, so
forgive me if you already gave answers to the following questions in that magazine:
1) What is the maximum power?
2) What could be the impedance of the headphones?
3) Did you try the circuit with other opamps? If so, with what results?
Thanks a lot for your attention.
I'm waiting for the issue of CHF that I ordered, so
forgive me if you already gave answers to the following questions in that magazine:
1) What is the maximum power?
2) What could be the impedance of the headphones?
3) Did you try the circuit with other opamps? If so, with what results?
Thanks a lot for your attention.
why talk about power? we live in a strange world and some politician might make a tax on our amps 
Headphone impedence 32-120 ohm. For 600 ohm impedence depends on their sensitivity, in same models the volume may be low.
I have not tried other operational amplifiers. I think a OPA2134 is designed for audio applications. It could be a valid and economical alternative.
Headphone impedence 32-120 ohm. For 600 ohm impedence depends on their sensitivity, in same models the volume may be low.
I have not tried other operational amplifiers. I think a OPA2134 is designed for audio applications. It could be a valid and economical alternative.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.