Well I bought one of the Chinese tube pre-amps off the auction site ...to mate up with the blue board version..it arrived yesterday and it's having a problem one channel is louder than the other...otherwise this amp to me sounds better than all my vintage receivers and I have the Lepai LP7498E 200 watt amp from parts express..it bests that too...are there any affordable decent sounding solid state pre amps out there?
I was also searching for a preamp and I found this on ebay
what I like in this design is that it has +/- 15 dB bass and treble boost at 40 Hz and 16 Khz and also loudness control for small bass enhancement during silent volume listening; all the modern pre/amplifiers have only +/- 10 dB at a very annoying frequency of 100 Hz (bass) and 10 khz (treble)
it costs only 22 $ with free shipping
An externally hosted image should be here but it was not working when we last tested it.
what I like in this design is that it has +/- 15 dB bass and treble boost at 40 Hz and 16 Khz and also loudness control for small bass enhancement during silent volume listening; all the modern pre/amplifiers have only +/- 10 dB at a very annoying frequency of 100 Hz (bass) and 10 khz (treble)
it costs only 22 $ with free shipping
everytime i put ebay link this forum truncates it, but search in ebay LM4610 and some of the boards available in different designs will appear...this one will also be among them
Regarding eBay links... Try the Google URL shortner @ goo.gl. Works everytime. 🙂
Guys how does the TPA3116 compare to a TPA3121 ?? I have a TPA3121 amp and although it is good, I'm not sure it's the giant-killer the TPA3116 is reported to be?
Quick update; I informed the vendor of the blue YJ board about the fact, that resoldering brought no results. And as expected, interest in communication ceased from their side.
Then I changed the 1000µF caps for Panasonic FM 1800µF, which brought more bass slam and control, but a tiny little bit aggressive highs as well.
Then I changed the two bigger input caps for my favourite mix, and the slight harshness dissapeared, sound is very pleasing now.
I think I will order another one, hopefully this time a cool one. Or maybe it sounds that good because of the heat, who knows 😉
This is one of the best values in audio, thats for sure, ridiculously good for the buck.
But the tube magic is not there, even with tube preamp.
BTW those amps do sound MUCH better with a preamp in my experience, i never use those pots.
Then I changed the 1000µF caps for Panasonic FM 1800µF, which brought more bass slam and control, but a tiny little bit aggressive highs as well.
Then I changed the two bigger input caps for my favourite mix, and the slight harshness dissapeared, sound is very pleasing now.
I think I will order another one, hopefully this time a cool one. Or maybe it sounds that good because of the heat, who knows 😉
This is one of the best values in audio, thats for sure, ridiculously good for the buck.
But the tube magic is not there, even with tube preamp.
BTW those amps do sound MUCH better with a preamp in my experience, i never use those pots.
I have been reading alot of this thread, but not all of the posts.
I have come to conclusion, that I should get two blue YJ boards, since they seems to be the best at the moment(?).
I would be putting them in same enclosure and driving both from the same sound source, thus making 4x50W system.
If I understood it right, one should sync these boards. I see there is a sync pin on the IC, but how is the synchronization actually made? More preferably what to solder on the boards?
Sorry for bad english.
I have come to conclusion, that I should get two blue YJ boards, since they seems to be the best at the moment(?).
I would be putting them in same enclosure and driving both from the same sound source, thus making 4x50W system.
If I understood it right, one should sync these boards. I see there is a sync pin on the IC, but how is the synchronization actually made? More preferably what to solder on the boards?
Sorry for bad english.
Got the YJ 2.0. Switched to 32db gain, swapped the large 1uf for other polyprops, swapped in 1kuf Muse PS caps. Sounds promising, definitely better than the red board any of the other boards I've used. Just a little bit trebly though so dunno if that's filter or components or what. But other than it's *much* better than the other boards. So much more realism and microdetail. This chip is so good its ridiculous.
Last edited:
The little egde should disappear after some hours of use. I left it powered for 2 days, and it smoothened quite a bit. But it is already good in stock form.
Last edited:
The YJ 2.0 is so much easier to mod than any of the other boards. Big win for clumsy solderers like me.
I still find that higher gain has a wider, more dimensional presentation. 32 or 36db just sound more impressive to me. Anyone else play with the gain?
I still find that higher gain has a wider, more dimensional presentation. 32 or 36db just sound more impressive to me. Anyone else play with the gain?
Hi wushuliu,
can you point me out a posting in this thread where was discussed about what resistor needs to be changed for what specific value so that gain is changed from stock 26 to 32 or 36? I ordered the red board with potentiometer so I would need new resistor values for that specific one, thanks
can you point me out a posting in this thread where was discussed about what resistor needs to be changed for what specific value so that gain is changed from stock 26 to 32 or 36? I ordered the red board with potentiometer so I would need new resistor values for that specific one, thanks
there is a 20k and 100k resistor next to each other (somewhere between the 3-pin input and the pot).
the datasheet says:
20k & 100k -> 26db, 30k impedance
39k & 100k -> 32db, 15k
47k & 75k -> 36db, 9k
Unlike most other amps, class D amp generally sound better the closer they are to clipping (without actually clipping naturally).
Interesting. Have to say Saturnus you've been a great resource on these chips. Thanks for all your input.
No problem. The very nature of the sound characteristics of class D amp and to save the most power is the reason I'm interested in class G or H implementation of class D with variable voltage to the output stage to keep it constantly just below clipping, something like -12dB average under peak. So for the TPA3116 chip for example you'd have a ultra-fast ultra-high efficiency burst mode buck-boost converter running at the same or higher clock frequency as the chip (typically you'd let the dc-dc converter be the clock master and all associated output chips would be slaves) and adjusting the voltage to the PVCC pins (not the AVCC pin, you'll need a separate supply for that) from say 5V to 20V which is a 12dB difference. It could be in 2-3 hard steps or totally analogue to the input signal. You'd need a input buffer that can similarly lower the input signal so that about half the total gain is from the adjustable voltage supplied output stage and half is from the input gain.
It would also cut the power consumption to a fraction as the chip only uses about 12mA quiescent current at 5V compared to about 27mA at 20V, or translated to watts, 60mW and 540mW respectively.
Okey I figured out how the syncing is done. Needs to change gain resistors and connect sync pins with a resistor. Found it from the datasheets, should have checked it before asking.
But I'm still wondering if the sync pin is accessible somewhere on the board in the blue YJ. Soldering straight to IC pin is probably above my soldering skills. Has anyone connected two separate boards?
in 36db gain setting a 1 uF input cap creates a high pass filter that starts to attenuate at ~175hz, playing around with gainsetting on very sure 3110 I personally found that most noticable, so I chose 20dB with 1uF with 3110, with 3116 I will try again, the clipping point might be closer all the time with little 3110 compared to 3116 LOL
noise level also nicer with 20dB gain on filterless sure3110!
noise level also nicer with 20dB gain on filterless sure3110!
Last edited:
