AudioSector-chip amp kits, dacs, chassis

JHelms · 2007-08-27 7:10 am

Ok new pics

All in the proper place *LOL* Not quite as perfect as the first time around but clean enough for me. Was a pain de-soldering the caps and re-installing them :bawling:

An externally hosted image should be here but it was not working when we last tested it.

rickmcinnis · 2007-08-27 8:54 pm

a DANIEL LME49810 based amplifier?

Just wondering if there is any chance you might be experimenting with this.

What do you think of it?

Any chance of making aPCB?

Thanks,

Rick McInnis

Peter Daniel · 2007-08-27 9:31 pm

I'm not really into those driver chips, but you can get nice boards from here:

http://www.chip-pcb.cn/7300/49810-A.htm
http://www.diyaudio.com/forums/showthread.php?postid=1248269#post1248269

rickmcinnis · 2007-08-27 10:35 pm

I had seen those ...

I have heard some interesting rumblings about these things and thought MAYBE you had some ideas for implementation.

What is responsible for your hesitation in using these? If there is anything more to it than time?

It seems like the next step from the LM3875.

Thanks,

Rick McInnis

richyrich212t · 2007-09-02 2:39 am

Peter,

what are "cz" and "Rz" used for on the lm4780 kit ??

Greg Erskine · 2007-09-02 2:53 am

z=zobel

arild · 2007-09-02 10:18 am

Bridge peter's LM3875

HI
this is my first post on the forum, i currently have the CT101 line stage from DACT http://www.dact.com/html/line_stages.html i would like to use peter's NOS DAC and four of his LM3875 ampifiers bridged into two 100W mono blocks, what do i need to do to bridge them since neither the DAC nor Pre have balanced outputs? could i us a transistor that changed the phase 180 degree's and if so does anyone have any suggestions for transitor type an a circuit for this? i found this on elliott's page http://sound.westhost.com/project14.htm i suppose this would work but looking for other designs as well. I would appreciate any comments to this setup since i am a newbie, i would like some recommendations. Even though my speakers are sensitive 95db i would like to pursue a higher power setup unless you guys strongly disagree!

Thank You

Arild:

AndrewT · 2007-09-02 10:34 am

Hi,
bridged suits high impedance loads.
It produces twice the power into double the load impedance.
However, current becomes the limiting factor.
50W into 4ohms is a very demanding spec for a chipamp, even though many builders go this route.
I would recommend you aim for 30W into 4ohms and and when bridged will give 60W into 8ohms. This will give about 108db maximum at 2.5m with your speakers. That is a very high level.

Alternatively, just go single and aim for 50W to 60W into 8ohms.
If your speakers are of a severe load type then consider parallel operation. This overcomes the current limit difficulty.

luvdunhill · 2007-09-02 2:33 pm

Peter:

I saw a recent post of your linking to where you describe some mods to the Meitner bidat. I currently own one and love it. Given this, do you have a recommendation for a NOS DAC kit, and how does it compare to the Meitner? Any kits that use the TDA1547 that have a similar flavor (or better!) than the bidat?

Thanks!

arild · 2007-09-04 12:15 am

HI Andrew

Thank you for the information, That would simplify things a little as well since i am a newbie. I can always try to parallel and such later to see what works best for my speakers. I have to decide on what amp to start with, i was set on the LM3875 but should i go for the LM4780? heck maybe i will just order both and find out for myself, as long as i can use the same power supply looks like the LM4780 are quite flexible to supply voltage http://www.national.com/cat/?i=289. Do you have a preference between the two amp's

Thanks
Ari

tangen · 2007-09-04 7:32 am

Peter Daniel's phono amp

Here is the schematic of VSPS based phono stage using Allen Wright's modified curve, with the additional zero at 3.2 µS.

Post #1553

Dear Peter.

Are you aware of that your phono amp gives your DAC some serious competition? I ordered two Cinemag CMQEE-3440A transformers and hook them up before your phono amp. This combo really plays music! I haven't tried the S&B transformers you use. But they have to be really good if they shall defend their price tag.

But the sound is of course first of all determinded by your phono amp. You have to produce this commercially! The music lovers deserve it! I have not played music on the cd player/dac combo for a week.

Thanks again for your offer and giving me this opportunity to have this gem of a phono amp.

Best wishes
Jan Ove

PS If you come of with other products that offer this musical quality, you have to tell me ;-)

Peter Daniel · 2007-09-06 2:14 am

Hi Jan,

I'm glad you like that phono amp. For anybody intersted, the circuit was described here: http://www.diyaudio.com/forums/showthread.php?postid=1123520#post1123520 (RIAA section based on VSPS)

It was actually the first phono stage that I've built recently and the one that I still have the biggest sentiment for. I later tried phono cube clone (the real one) and Pass Ono, but none of those played that good without the need for extensive mods and tuning. In fact, none of that is completed yet.

Below picture of my original setup.

Peter Daniel · 2007-09-06 2:28 am

arild said:
I have to decide on what amp to start with, i was set on the LM3875 but should i go for the LM4780? heck maybe i will just order both and find out for myself, as long as i can use the same power supply looks like the LM4780 are quite flexible to supply voltage http://www.national.com/cat/?i=289. Do you have a preference between the two amp's

I have a preferrence for LM3875 and that's what I use in all my commercial amps. Parallel LM4780 is mostly recommended for low impedance loads, where higher power is desired.

I still use LM4780 in bridged configuration in one of my systems and it performs well. Probably the easiest way to get balanced signal from unbalanced source is to use matching transformers. Here's the affordable solution that performed really well (I tried it): http://www.edcorusa.com/products/transformers/wsm/wsm10k-10k.html

Peter Daniel · 2007-09-06 2:38 am

luvdunhill said:
I saw a recent post of your linking to where you describe some mods to the Meitner bidat. I currently own one and love it. Given this, do you have a recommendation for a NOS DAC kit, and how does it compare to the Meitner? Any kits that use the TDA1547 that have a similar flavor (or better!) than the bidat?

According to some, a modified Bidat is one of the best DACs available, at any price. Well, I have one and I think it may be true

I described some of my mods here: http://www.diyaudio.com/forums/showthread.php?postid=901594#post901594 I later did a bit more, which I did not described.

I bought that unit more than a year ago and it's been in my system ever since. Initially, it didn't sound to me as good as the modified NOS DAC, although I could detect some hidden potential. After the mods, I would say it's some 10-20% better than NOS DAC, it has more refinement, when NOS can be still a bit rough on the edges or a bit colored. NOS DAC on the other hand offers probably more raw energy.

For best results, Bidat needs to be modified, otherwise it sounds veiled and a bit boring.

Peter Daniel · 2007-09-06 2:41 am

richyrich212t said:
Peter,

what are "cz" and "Rz" used for on the lm4780 kit ??

Those parts are described in the schematic that is supplied with a kit, or can be found on my website:

http://audiosector.com/lm4780 amp.pdf
http://audiosector.com/lm4780 psu.pdf

Cz and Rz are optional Zobel parts. I don't use them with the kits as they affect the sound in a way that should be avoided.

Peter Daniel · 2007-09-06 2:45 am

Re: I had seen those ...

rickmcinnis said:
I have heard some interesting rumblings about these things and thought MAYBE you had some ideas for implementation.

What is responsible for your hesitation in using these? If there is anything more to it than time?

It seems like the next step from the LM3875.

For me a next step from the LM3875 would be F3 or F4.

Somehow, I don't feel tempted to add output devices to the chips; it's either chip by itself or completely discreet circuit.

ttan98 · 2007-09-06 3:31 am

Peter,

what happen to your DAC, last time I visited I could find any on sale?

Peter Daniel · 2007-09-06 3:39 am

ttan98 · 2007-09-06 3:46 am

all links are upgrades and fixes, if i am interested in BUYING one should i talk to directly?

since you are here, questions incl.:

1. Price
2. options
3. technical specs.

many more, that is why you should put info on yr site rather than repeating yourself.

Peter Daniel · 2007-09-06 3:47 am

BTW, recently a customer who bought one of the DACs some years ago asked to have it modified into balanced version.

Here's how it came out ( I added another DAC board, the circuit reversing DATA phase is glued to receiver chip).

AudioSector-chip amp kits, dacs, chassis

Member

Member

Member

Member

Member

Member

Member

R.I.P.

Member

Member

Member

Member

Attachments

Member

Member

Member

Member

Member

Member

Member

Member

Attachments