Hozone-
The Zoom pedal you are using can create some 'tube effects' and distortion, I assume.
So you can use that chipamp board as a power amp.
Plenty of power if you use a guitar amp speaker - don't use a hifi speaker as it will not sound good for guitar. A 5 watt tube guitar amp is plenty loud for playing at home or in quiet venues, recording, etc.
You could also try one of the mono chip amps from ebay, as I think the amp you are considering is stereo?
I'm a tube amp guy for guitar, myself, but your idea should work OK.
Don't worry about any hifi 'mods' for your chip amp - guitars love distortion, so standard capacitors, etc work just fine. Just use the amp 'as-is' and save your money for a decent speaker and cabinet.
Please start a thread and post some pictures of your amplifier. Good luck with your project!
John
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Good speakers. I keep looking on ebay to upgrade, but I love my linn indexes on stands. Simples! My amp will be ready soon, just needs tranies and pot. will post pics next week.
Barry
Barry
thank you,
i've finally tried a TDA7294 chip amp from ebay, but only thinks i have to try is a 20-0-20V 180VA transformer, it sounds good but power to low, i suppose it's for the voltage, but not sure of this.
i've finally tried a TDA7294 chip amp from ebay, but only thinks i have to try is a 20-0-20V 180VA transformer, it sounds good but power to low, i suppose it's for the voltage, but not sure of this.
The tda7294 datasheet shows the range of suitable supply voltage as +-10Vdc to +-40Vdc.
Your 20+20Vac transformer fits within this range.
Look at the two graphs for output power (into 8r0 and 4r0) for the full supply range. Your 20+20 will give ~+-30Vdc so you are towrds the top end of supply voltage for both 6ohm and 8ohms speaker load.
Too high for a 4ohm speaker load.
Either you have set up your amp incorrectly or your speakers are too inefficient to work with a chipamp.
This is a 3886 thread.
Ask the Moderators to move your enquiry to a more suitable thread or to open a new thread for your chipamp.
Your 20+20Vac transformer fits within this range.
Look at the two graphs for output power (into 8r0 and 4r0) for the full supply range. Your 20+20 will give ~+-30Vdc so you are towrds the top end of supply voltage for both 6ohm and 8ohms speaker load.
Too high for a 4ohm speaker load.
Either you have set up your amp incorrectly or your speakers are too inefficient to work with a chipamp.
This is a 3886 thread.
Ask the Moderators to move your enquiry to a more suitable thread or to open a new thread for your chipamp.
Finally finished my latest project. Yuanjing Amp with usb and sd card slots. Sounds very good but needs some mods. The sd unit has a small internal amp which I don't want. Just got to sort out where to connect to disable it. I used a 25+25 transformer which gives about 30v so should be ok for now. I have a slight hum which seem to come from the RS alps pot on one channel, I can only assume the pot is faulty so will replace that for a dact type in the future and all should be well. Will also change the op-amps later. I will post some pics
Barry - cool stuff. I haven't played with the Yuanjing for a while now, but I'll put my previous build(s) into an old amplifier chassis later.
Right now, I'm working on and have built about 6 Mauro Penasa MyRef Rev C boards, and they're in an altogether different class, above the stock Yuanjing. I'd highly recommend the MyRef - it has extraordinary sonics which one would not usually attribute to a chipamp/gainclone.
Right now, I'm working on and have built about 6 Mauro Penasa MyRef Rev C boards, and they're in an altogether different class, above the stock Yuanjing. I'd highly recommend the MyRef - it has extraordinary sonics which one would not usually attribute to a chipamp/gainclone.
Barry - as always, your workmanship is excellent. I have one of those MP3 decoder boards with USB port and remote, but without the nice red LED display and card reader that you've built. Thanks and Merry X'Mas.
Nice one Barry!definitley the way of the future. I nearly did a similar thing to my yuenjing but decided to Ill get apple aiport as i use itunes alot.
I have nearly finished my yuenjing triamp with active crossover project. i am have just tested to make sure the amps are all working as i have messed around alot getting them on a heatsink!!
Having no volume pot connected and plugged into laptop for audio there is quite alot of noise presumably as they run at full gain.They didnt do this with an alps pot connected at the jumpers.
Is this norm when used as a power amp? i presume this will also happen with xover as well
Linux guru any thoughts?
I have nearly finished my yuenjing triamp with active crossover project. i am have just tested to make sure the amps are all working as i have messed around alot getting them on a heatsink!!
Having no volume pot connected and plugged into laptop for audio there is quite alot of noise presumably as they run at full gain.They didnt do this with an alps pot connected at the jumpers.
Is this norm when used as a power amp? i presume this will also happen with xover as well
Linux guru any thoughts?
Thanks skodaboy, I think a pot at the jumpers is better, but Linuxguru will know best. Iv'e tried at input and at jumpers and cannot find any difference. Barry
Nice build... but those live mains connections to the iec socket filter look dangerously exposed!
BITF
BITF
Yes, I have had a few wacks from that and the on-off switch whilst fiddling about,but not as bad as some commercial stuff. I could heat shrink them, but it will not improve the sound! lol
I just finished reading this whole thread, and am impressed that it's still alive! Sweet! Opamps and ebay listings are dancing in my head.
Okay, i'm currently doing the first mod detailed by linuxguru -- the diagonal resistor and the vertical 10R to reduce hum. I understand that increasing the resistance on the input increases the gain, okay, so which resistors are we talking about? Should i change the 22k resistor that jumps its neighbor and that neighbor to 47k resistors? I built a minimalist point to point chipamp that i ADORE and use daily, but this more complex circuitry is over my head.
Next question: can i use one pot for all the in-out-gnd jumpers, or will connecting them basically bridge the input channels?
Last question:Should I just rip the components off these boards and construct point-to-point amps?!? SO MUCH SIMPLER!!!! (And i'm kidding...😀) ...but if i can't make these sound like i want, that's totally what i'm going to do. It's cheaper to buy these boards than it is to buy the LM3886's and smoothing caps individually.
Okay, i'm currently doing the first mod detailed by linuxguru -- the diagonal resistor and the vertical 10R to reduce hum. I understand that increasing the resistance on the input increases the gain, okay, so which resistors are we talking about? Should i change the 22k resistor that jumps its neighbor and that neighbor to 47k resistors? I built a minimalist point to point chipamp that i ADORE and use daily, but this more complex circuitry is over my head.
Next question: can i use one pot for all the in-out-gnd jumpers, or will connecting them basically bridge the input channels?
Last question:Should I just rip the components off these boards and construct point-to-point amps?!? SO MUCH SIMPLER!!!! (And i'm kidding...😀) ...but if i can't make these sound like i want, that's totally what i'm going to do. It's cheaper to buy these boards than it is to buy the LM3886's and smoothing caps individually.
I recommend getting the bare board and the parts separately - it's more expensive, but you have full control over the parts quality. There were some posts earlier that expressed doubt about the authenticity of some of the parts in the fully-built boards, including the chipamps and coupling caps.
I posted the resistor changes (with some pics) earlier - I think it involved using a 27k carbon-comp instead of a 22k near the chipamp.
You can use a dual-gang pot connected at the jumper block between the op-amp and chipamp, but the wiring to the pot may be prone to pickup. The recommended op-amp upgrade is the LM4562 instead of the NE5532.
If you want an LM3886 amp with far better sonics than this one, consider the Mauro Penasa MyRef RevC. It's more elaborate and expensive than this one, but also in an altogether different plane when considering audible sonics. Almost everybody who has built one agrees that the MyRef beats just about any solid-state power amp in the $1k-$10k range.
Linuxguru,
I want to clone your new creation and sell it for as much as I can get from anybody that has no scruples with copyright, Patent, Intellectual Property rights etc.
Please post a high resolution, in focus, good contrast, close up pic of both sides of your PCB so I can copy it for least effort.
I want to clone your new creation and sell it for as much as I can get from anybody that has no scruples with copyright, Patent, Intellectual Property rights etc.
Please post a high resolution, in focus, good contrast, close up pic of both sides of your PCB so I can copy it for least effort.
What are those other two boards there besides the LM3886 amp? Speaker protection? And?
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