Good morning all,
My name is Tony and I am a craftsman from Switzerland. I am above all a passionate music lover and also a designer. This gives me the opportunity to express and share my design philosophy through my creations and / or my devices.
For listening with headphones I made 2 devices that I present to you here: The first one that the EC99 is part of the OTA range
Détails : Amplificateur casque SE 99
greeting
My name is Tony and I am a craftsman from Switzerland. I am above all a passionate music lover and also a designer. This gives me the opportunity to express and share my design philosophy through my creations and / or my devices.
For listening with headphones I made 2 devices that I present to you here: The first one that the EC99 is part of the OTA range
Détails : Amplificateur casque SE 99
greeting
Last edited:
Hello,
Absolutely yes.
The Lundhal output transformer used has a specific winding with a 12: 1 ratio in order to connect hall standard 32R headphone to it.
This same transformer also has two other dedicated windings to connect an impedance and / or headphones of 150R or even 600R.
As you can imagine the lundhal is an important and high quality component. However, with this device I offer the possibility of using other transformers at a lower cost.
See the list of options. For info, I offer excellent Asian transformer with Amorphous core.
greetings. Tony
Thank you for the compliment and for answering your question ...
Absolutely yes.
The Lundhal output transformer used has a specific winding with a 12: 1 ratio in order to connect hall standard 32R headphone to it.
This same transformer also has two other dedicated windings to connect an impedance and / or headphones of 150R or even 600R.
As you can imagine the lundhal is an important and high quality component. However, with this device I offer the possibility of using other transformers at a lower cost.
See the list of options. For info, I offer excellent Asian transformer with Amorphous core.
greetings. Tony
"I offer excellent Asian transformer with Amorphous core"
Do you offer them as spare parts for other DIY'ers?
If not then your amp should be moved to the "Commercial/trading" thread and not presented here...
Do you offer them as spare parts for other DIY'ers?
If not then your amp should be moved to the "Commercial/trading" thread and not presented here...
Hello Franck,
If you wish, you can consult and discuss in my dedicated thread here:
New e-shop for DIY and electronic tube made in Switzerland
Yes I can. However, For reasons of cost and shipping costs I only do it for the European Union.
I just wanted to show what I do and how.
If you wish, you can consult and discuss in my dedicated thread here:
New e-shop for DIY and electronic tube made in Switzerland
My beta22
Built my beta22 years ago. Enclosure is home made with aluminum sheets and mahogany sides.
Built my beta22 years ago. Enclosure is home made with aluminum sheets and mahogany sides.
Attachments
Last edited:
This thread has gone stale, so here is a recent project. I think of it as a Crossfeed Sandbox, since it includes three Meier-style (enhanced bass) Crossfeed settings, all in sockets so I can play with different resistor/capacitor values. The simple discrete buffers are my own design.
The top does fit on this, but I leave it off so I can easily swap crossfeed components, and because I haven’t yet installed a battery door.
The top does fit on this, but I leave it off so I can easily swap crossfeed components, and because I haven’t yet installed a battery door.
Another picture in the well-known wild style.
A picture of my headphone amplifier. Some more info can be found here (I was active on this forum before as EL504, which became 32860 when disabled): "Aikido" headphones amp with ECC40 and E182CC
SE triode headphone amp designed by a good friend, Rene'.
0D3 voltage reg tubes/5842 output tubes.
Khozmo 48 step attenuator.
ONetics output transformers.
Padauk/Walnut and aluminum top plate.
Sennheiser HD600 phones on cherry stand.
Really happy with the sound.
0D3 voltage reg tubes/5842 output tubes.
Khozmo 48 step attenuator.
ONetics output transformers.
Padauk/Walnut and aluminum top plate.
Sennheiser HD600 phones on cherry stand.
Really happy with the sound.
Attachments
It is basically the schematic in
https://www.diyaudio.com/community/threads/a-basic-discrete-buffer.374389
One issue with the buffer is that the passband is too large, so I did need to add an input low-pass filter to reduce EMI-induced noise. I used 1.5k resistor and 330pF capacitor. It is soldered on the green pcb and not visible in the photos above.
I can post the gerbers - I will try to do that later this weekend in the thread about the buffer - it will take some time as I will need to make sure I include enough information with them (parts list, schematic with correct labels, etc) so that they will be useful. However, this is the first board I have ever designed, so I'm sure I made many rookie mistakes. For one the traces are very thin - not sure what I was thinking with those! I ordered them from Oshpark and just shared them so you can see for yourself:
https://oshpark.com/shared_projects/5WctCoeP
By the way the $20.80 US price included delivery inside the US and 3 copies of the board.
jason
.
I guess I will revive this thread...
Here are a few portable discrete amps/buffers. Each includes crossfeed, uses a single-supply design with class-AB output inside a global feedback loop, and draws around 12 mA idle.
Brief descriptions
1. bipolar complementary-feedback pair; gain = 1.
2. actively-loaded LTP input that directly drives output (2-stage opamp); gain=1.4.
3. JFET common-source input that directly drives output; gain=-1. Has high H2 distortion but I like it anyway.
Playing with simple designs like these is a fun way to learn more about transistor circuits. I use them all the time because of the crossfeed.
jason
Here are a few portable discrete amps/buffers. Each includes crossfeed, uses a single-supply design with class-AB output inside a global feedback loop, and draws around 12 mA idle.
Brief descriptions
1. bipolar complementary-feedback pair; gain = 1.
2. actively-loaded LTP input that directly drives output (2-stage opamp); gain=1.4.
3. JFET common-source input that directly drives output; gain=-1. Has high H2 distortion but I like it anyway.
Playing with simple designs like these is a fun way to learn more about transistor circuits. I use them all the time because of the crossfeed.
jason
Attachments
Nice work, Jason! Do you have any DC offset protection in your circuits? Although a 9v battery probably won’t damage all but the most sensitive IEMs.
They all have output capacitors with 1k bleeder resistors, so DC shouldn’t be a problem. I should have added that detail to the ‘single-supply’ part of the description.
The jfet-input device might not be the best for sensitive IEMs. I don’t have equipment that allows me to measure the noise floor, but it uses shunt feedback with 51k resistors so will be noisier than the others. I wanted the high resistance for input impedance after the crossfeed, and as a bonus it improves stability with capacitive loads. All of the units have <20% overshoot in square-wave response with pure 2nF loads.
On the other hand, both the jfet and the ltp amps have an optional output attenuator (33R and 3.3R volttage divider) that can be enabled with a jumper visible in the photos. I don’t listen loud so like that option, and it only makes the output impedance a maximum of 3.3 Ohms. For sensitive IEMs perhaps other voltage-divider values would be better to give a lower output impedance.
The jfet-input device might not be the best for sensitive IEMs. I don’t have equipment that allows me to measure the noise floor, but it uses shunt feedback with 51k resistors so will be noisier than the others. I wanted the high resistance for input impedance after the crossfeed, and as a bonus it improves stability with capacitive loads. All of the units have <20% overshoot in square-wave response with pure 2nF loads.
On the other hand, both the jfet and the ltp amps have an optional output attenuator (33R and 3.3R volttage divider) that can be enabled with a jumper visible in the photos. I don’t listen loud so like that option, and it only makes the output impedance a maximum of 3.3 Ohms. For sensitive IEMs perhaps other voltage-divider values would be better to give a lower output impedance.
Cool - coupling caps are a good way to go. I wasn’t sure if you might be doing DCDC converter for dual rails.
Since the thread is coming back, I will add my amp to the bunch. It has been a long time ago now, but I built this Glassware Audio HP amp using an old power amp chassis that I thought would be thrown out. Took a lot of work but the result was the best sounding HP to date for me. Uses 6GM8 tubes for the input and I don't remember the model but it uses voltage regulators for the output! I just had to try it out.
