Hi, first post. A year ago I bought the Sure Electronics 20/24 amp, really loved it driving my JBL
L5's (6ohm). This week I stepped it up and ordered two Sure Electronics TDA 7492's, more power same decent build quality I hoped. I installed the first one at work with a pair of A/D/S L720/2 speakers. Sounded great but no volume whatsoever. Thought it was the effiency of the speakers. Then i swapped the Sure for my Lepai at half the cost of the Sure and half the power. Lepai drives the A/D/S speakers just fine, so much louder, and they don't hsve to go so loud. This makes me wonder about gain. I'm perplexed. The Sure sounds good at home with my JBL's, but not appreciably more powerful than the first Sure. Ideas?
L5's (6ohm). This week I stepped it up and ordered two Sure Electronics TDA 7492's, more power same decent build quality I hoped. I installed the first one at work with a pair of A/D/S L720/2 speakers. Sounded great but no volume whatsoever. Thought it was the effiency of the speakers. Then i swapped the Sure for my Lepai at half the cost of the Sure and half the power. Lepai drives the A/D/S speakers just fine, so much louder, and they don't hsve to go so loud. This makes me wonder about gain. I'm perplexed. The Sure sounds good at home with my JBL's, but not appreciably more powerful than the first Sure. Ideas?
I just ordered one of these from parts express also picked up the volume board.
claims 20watts stereo at 4 ohms. Seems to be under powered according to the spec sheet.
claims 20watts stereo at 4 ohms. Seems to be under powered according to the spec sheet.
These were built amplifiers, not the raw boards. I was wondering if their is an internal gain inside on the board?
The chip has 4 preset gains, and the lowest is only 21.6dB, which isn't even 20x. I guess the original has probably 30x gain. So the chances are that it's not running out of power, just needs more signal. The gain is set on pins 30 an 31. If those are tied the Ground and there isn't a 3.3V supply, then that's your explanation. If there is a 3.3V supply, then you can set one or both of the pins to 3.3V and vary your gain.
Page 22, here: http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/CD00205863.pdf
Page 22, here: http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/CD00205863.pdf
Ni idea. You may have to count the pins, if it's not marked on the board. Then measure the voltage on the pins. Otherwise what you are looking for is a small regulator else, or perhaps a test point that says 3.3V (fat chance probably). If you're lucky it might be a 7805 with a zener after if. Maybe an LM317 (at all of 10p) in a TO92 case (so like a transistor.
I bought a headphone amp on ebwy. Guy makes them in mint boxes CMOY based. Its between source and amp. Sounds excellent now. Not sure why they would ship them this way.
I now love this amp. I use a preamp with it, an interesting pre, handmade in Charlottesville, Va, right up the road from me. Amber is the brand. The gain on this amp is set low, yet it rocks, is deep, clear and sparkly when it gets proper input. I have also added a powered sub(Lab 12 in a sealed 1.5 cu ft box, powered by a Bash 300). Bliss.
- Status
- Not open for further replies.