Hi Herman,
You'll get very close to 12W into your tweeters with the stock (LME49990) LPUHP setup. This correlates to about 120dB/1m. For me, that's more than enough, but given the higher impedance, the amp would take nicely to the over-volt mod. You would get back to the full 16W of output power into 12 ohms, for a final output of about 121dB/1m.
With dual 15V secondaries you will not have to get the supply rails up to the desired 22VDC. You will need +/-18V secondaries to have enough headroom on the unregulated supply to keep the regulators happy.
As for chassis, I haven't run across anything canned that I would specifically suggest, but if you look back through this thread, there are many great examples that others have built!
Regards,
Owen
You'll get very close to 12W into your tweeters with the stock (LME49990) LPUHP setup. This correlates to about 120dB/1m. For me, that's more than enough, but given the higher impedance, the amp would take nicely to the over-volt mod. You would get back to the full 16W of output power into 12 ohms, for a final output of about 121dB/1m.
With dual 15V secondaries you will not have to get the supply rails up to the desired 22VDC. You will need +/-18V secondaries to have enough headroom on the unregulated supply to keep the regulators happy.
As for chassis, I haven't run across anything canned that I would specifically suggest, but if you look back through this thread, there are many great examples that others have built!
Regards,
Owen
Owen,
is there anything else we need to change for the "over-volt mod", other than transformer and driver opamp?
I'll be using SE inputs and high gain.
Thanks,
Herman
is there anything else we need to change for the "over-volt mod", other than transformer and driver opamp?
I'll be using SE inputs and high gain.
Thanks,
Herman
There is a BOM somewhere in this thread.
- Input caps need to be increased to >25V
- Voltage set resistors for regs need to be changed for +/-22V rails
- Make sure all bypass caps are at least 25V rating after the regs.
Regards,
Owen
- Input caps need to be increased to >25V
- Voltage set resistors for regs need to be changed for +/-22V rails
- Make sure all bypass caps are at least 25V rating after the regs.
Regards,
Owen
This BOM is for the overclocked LPUHP with SE input and 7.5db gain: http://www.diyaudio.com/forums/soli...lpuhp-16w-power-amplifier-13.html#post3867857
Are there many member here driving the LPUHP with BAL-BAL as preamp?
What concern do you have regarding to this issue?
What concern do you have regarding to this issue?
Wondering the same, I hope the pcb buy is still active?
LME49990 is EOL now. However it can still be found on ebay at reasonable price at this moment. They are not expensive, so I stocked a dozen at hand.
As for alternative parts, spec wise I saw people mentioned OPA1611 as similar, but not sure (not even familiar with that family of products) it could be a direct replacement. Its pin definition is the same, though.
LME49600/49610 on the other hand, is more difficult to find at reasonable price on ebay now.
Opa1611 oscillating
About the opa1611 replacement...
I just built one channel yesterday substituting all LME49990s with OPA1611s and it oscillates at around 16MHz (which does correspond to a dip in the phase vs. freq graph for OPA1611, maybe some lead to chase there...) Will do more testing and tweaking this week and keep you updated.
About the opa1611 replacement...
I just built one channel yesterday substituting all LME49990s with OPA1611s and it oscillates at around 16MHz (which does correspond to a dip in the phase vs. freq graph for OPA1611, maybe some lead to chase there...) Will do more testing and tweaking this week and keep you updated.
Update on the OPA1611s:
10pF capacitors in parallel with the two feedback resistors for the third amplifier solved the oscillation problem. Now I have a flat response up to from DC up to 400kHz 😀
10pF capacitors in parallel with the two feedback resistors for the third amplifier solved the oscillation problem. Now I have a flat response up to from DC up to 400kHz 😀
summary?
Does anyone have a summary of current status?
I'd like to try making a couple. I haven't read entire thread
but chunks of it here and there.
opc, are you sending out boards/kits/partialkits/etc right
now?
You should consider taking donations--something like
a mandatory amount to cover your costs, and then
everyone could chip in an optional donation amount
based on how they liked it/what value it was to them.
Thanks
Allan
Does anyone have a summary of current status?
I'd like to try making a couple. I haven't read entire thread
but chunks of it here and there.
opc, are you sending out boards/kits/partialkits/etc right
now?
You should consider taking donations--something like
a mandatory amount to cover your costs, and then
everyone could chip in an optional donation amount
based on how they liked it/what value it was to them.
Thanks
Allan
Hi Noviygera,
Check out the schematic on the main Wiki:
The Wire - All Boards and Kits Explained Here!
If you're running in SE mode, you need to send the input to SE input and GND to GND. Follow the schematic for which parts need to be POP and DNP. There are large boxes around the input stage which clarify this.
Let me know if this is clear enough.
Regards,
Owen
Check out the schematic on the main Wiki:
The Wire - All Boards and Kits Explained Here!
If you're running in SE mode, you need to send the input to SE input and GND to GND. Follow the schematic for which parts need to be POP and DNP. There are large boxes around the input stage which clarify this.
Let me know if this is clear enough.
Regards,
Owen
Owen, can you clarify if there are suitable Opamps to replace obsolete/EndOfLife ones ?
Are PCB still available ?
Thanks a lot
Are PCB still available ?
Thanks a lot
If using 35v filter caps, would I be ok with 4700uf capacitance? They cost a lot less 🙂)
Even 6600uf cost less than the 5600uf in 35v rating.
Is it the case that more capacitance is better?
Even 6600uf cost less than the 5600uf in 35v rating.
Is it the case that more capacitance is better?
I use good quality, branded 4700u (blue ELNA). It's for the power supply section and won't impact to the sound, use only branded caps since they rating is true and they usually have better ripple.
Hi Owen,
I just found out about the LPUHP, and I’m already very exited about it 🙂
I’m considering using the LPUHP in my home cinema. My speakers have a sensitivity of about 93dB/W/m and are crossed over to the subs at 120Hz. The listening position is about 3m from the speakers. I’m a little concerned about the power rating though and have a few questions:
- How much power can the LPUHP deliver into a 4 ohm load?
- What is the idle consumption?
- What happened to the MPUHP? 🙂
Best regards
I just found out about the LPUHP, and I’m already very exited about it 🙂
I’m considering using the LPUHP in my home cinema. My speakers have a sensitivity of about 93dB/W/m and are crossed over to the subs at 120Hz. The listening position is about 3m from the speakers. I’m a little concerned about the power rating though and have a few questions:
- How much power can the LPUHP deliver into a 4 ohm load?
- What is the idle consumption?
- What happened to the MPUHP? 🙂
Best regards
Just wanted to put in a few good words about my recent build of LPUHP. Built it with no issues (over voltage version, 18v transformers). The sound:
I find the sound clear and natural with long term "listenability" or low long term fatigue. In a way, it reminds me more of a tube amp than a solid state amp, in a way that it is more holographic and less emphasis on the foreground sounds and more on the lower level texture and ambience. It's not a "hard" in your face sound but more subtle, yet not lacking in dynamics.
The emphasis is equal between the attack and decay. It's not focused on attack with dry decay, it's more like a tube amp with natural signature all around, very open and airy but NOT very warm. Perhaps low higher order harmonic distortion? Not sure how to articulate what I hear in technical terms but definitely a sound that growing on me.
Very good sound indeed.
I find the sound clear and natural with long term "listenability" or low long term fatigue. In a way, it reminds me more of a tube amp than a solid state amp, in a way that it is more holographic and less emphasis on the foreground sounds and more on the lower level texture and ambience. It's not a "hard" in your face sound but more subtle, yet not lacking in dynamics.
The emphasis is equal between the attack and decay. It's not focused on attack with dry decay, it's more like a tube amp with natural signature all around, very open and airy but NOT very warm. Perhaps low higher order harmonic distortion? Not sure how to articulate what I hear in technical terms but definitely a sound that growing on me.
Very good sound indeed.
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