2.2 -> 2.3 adds another pole in the RFI filter, so you get a little better filtering on the input. 2.3 also allows you to use my custom wound output inductor. I still give you the specs so you can wind your own, but if you'd rather skip the hassle, I do offer the output inductor as a component.
Tom
Tom
Fair enough, thank you again. If anyone else reading this has any experience with a tubes preamp previous to a modulus power amp, I'd appreciate any insight.
As per upstream, I have got a Parallel 86 amp running with a World Designs Pre 3 using balanced connections, which given the location in Europe may be an option for the next few weeks anyway...
Works very well from my point of view, but be prepared to drop the Modulus gain with a That1203 or 1206 depending on sources, speakers and listening levels.
Thank you for sharing the experience, didn't know about that one, looks good.
Yup, I actually saw that mod in the documentation just last week and had this in mind. Thank you
Hi, today I finished my 2-channel modulus-86 build... well actually not finished, because I am missing THAT1206 (its on a way), so i at least wanted to try to connect RCA into the input of LME49720. So I hardwired it on top of R23 because that was very convenient place to solder it on (dont need filters just for testing...) The amplifier came life without any problems - and it plays... But I am not so pleased with sound. I am playing into Dali Ikon 2 speakers with good cables that vere tested on very good amplifiers so I know they sound great.
It sounds a little better then LM3886 alone, but the sound is actually a little unpleasant, stage is not bad, but the instruments are not divided as i expected them to be (and as they are on some otgher amplifiers), soudn is unpleasant on bigger volume (which is always good indication it is distorted in some way or another)...
So my question is - did i do something wrong elsewhere or is connecting rca straight into LME49720 just not good idea because ths happens?
It sounds a little better then LM3886 alone, but the sound is actually a little unpleasant, stage is not bad, but the instruments are not divided as i expected them to be (and as they are on some otgher amplifiers), soudn is unpleasant on bigger volume (which is always good indication it is distorted in some way or another)...
So my question is - did i do something wrong elsewhere or is connecting rca straight into LME49720 just not good idea because ths happens?
Hi all,
I have two questions to the new versions of Modulus design regarding to the older ones:
- why had been omitted the DC-servo circuit, and placed some electrolytic (b.p.) caps there into the signal path?
- why had been omitted the THAT1200 diff. receiver and realized an instrumentation amp schematic with LM49720 ICs?
I simply do not understand it...
I have two questions to the new versions of Modulus design regarding to the older ones:
- why had been omitted the DC-servo circuit, and placed some electrolytic (b.p.) caps there into the signal path?
- why had been omitted the THAT1200 diff. receiver and realized an instrumentation amp schematic with LM49720 ICs?
I simply do not understand it...
The THAT1200 is the dominant noise source in the Modulus-86. To get lower noise floor, I had to design it out.
The DC servo adds about $10 worth of components. That may not sound like much ... until you build 100 of them. With a little bit of creativity in the design, I was able to get good DC performance without the DC servo, so I chose to save the money, board area, and assembly cost of the DC servo by getting rid of it.
The one electrolytic capacitor in the signal path is a bipolar type made by Nichicon. As you can see in all my measurements for the Modulus-186, -286, and -686, the cap is sonically transparent and allows the amps to provide world-class performance.
Tom
The DC servo adds about $10 worth of components. That may not sound like much ... until you build 100 of them. With a little bit of creativity in the design, I was able to get good DC performance without the DC servo, so I chose to save the money, board area, and assembly cost of the DC servo by getting rid of it.
The one electrolytic capacitor in the signal path is a bipolar type made by Nichicon. As you can see in all my measurements for the Modulus-186, -286, and -686, the cap is sonically transparent and allows the amps to provide world-class performance.
Tom
For the reference. Just another way of building Mod-86.
Thanks. Tom.
An externally hosted image should be here but it was not working when we last tested it.
Thanks. Tom.
