Anyone willing to help? Need dual pre-outs to my Don A. Pre

[Stuart Polansky]

Your amp is fine. The other two amps will present a big load to the preamp. If you use either, better buffer that output. Good news, it's easy to do and the FET won't affect the sound at all (to the upper range amp you use now.)

Excellent!

[FerdinandII]

Too bad the outputs on the DAC are fixed level..... It's got everything that you need:



If you feed the DAC with something like the Meridian 518, which has volume control on the digital output, you could eliminate the preamp.
The volume controls on the input of the bass amps would take care of the required level matching.
http://www.stereophile.com/digitalprocessors/367/index.html#LIcB8TiozpUtbLi3.97

I just happen to have a 518 lying around if you're interested in trying this option.......

[dkalsi]

Thanks Stuart and Ferdinand.

Stuart - is this something you can assist with?

Ferdinand - thanks for the kind offer. Could I not use the "volume control" in my computer?

The one think I forgot to mention was that I was going to use a MiniDSP to low-pass the singal at 150 - 200Hz to my flanking subs.

I also have a Behringer DCX2496 that I could use. Its currenly being used my home theater, but I haven't been using it recently.

Other equipment on hand: A diy passive-pre (seems to be nothing more than a volume control) and a Sonic Euphoria PLC Passive Pre.

Its about 7-years old though.

Last edited by dkalsi on August 6th, 2015, 9:12 pm, edited 1 time in total.

[FerdinandII]

Yes, I would start there.....

I know everyone talks about sonic degradation from digital volume controls, but I compared the Meridian 518 to an Alps 40mm Blue pot and the 518 won that one, easy..... The addition of one high quality pot in the analog signal chain put a thin haze on everything.

I'm the extreme in this group, though. I have only ONE line level interconnect in my system......

Ferdinand - thanks for the kind offer. Could I not use the "volume control" in my computer?

[FerdinandII]

How many digital outputs do you have on the sound card? If >1, just run the second one to the DCX2496 and use that one for the subs. You will have full control of delay in the digital domain, in case there is some issue. Maybe phase, too? I don't remember if the DCX can do that....

The one think I forgot to mention was that I was going to use a MiniDSP to low-pass the singal at 150 - 200Hz to my flanking subs.

I also have a Behringer DCX2496 that I could use. Its currenly being used my home theater, but I haven't been using it recently.

[Stuart Polansky]

I'll be around weeknights next week. Let's talk, I may be able to help.
Please send (internal and external) pictures and HOPEFULLY a schematic of what you have (preamp)!

Hopefully all that we will need is four resistors, two RCA jacks, two FETs, two diodes and a little wire.

Re volume controls. If you're gonna compare, compare the Lightspeed to a digital gain control. I don't know which wins, but unless you have a dual wiper set P&G, a pot doesn't stand a prayer compared to a Lightspeed. But, I completely agree Ferdinand II use the digital gain if you have one and can eliminate the line stage. Also, use the balanced output to balanced input of the power amps.

Then, the mod is to pull the pots from the power amps and replace them with LED gain sets!!!

Of course if you ever go vinyl, throw all that out!

[FerdinandII]

It did sort of pain me to suggest that someone stop using their tube preamp........
I still sorta miss mine.

[Roscoe Primrose]

Then, the mod is to pull the pots from the power amps and replace them with LED gain sets!!!!

I think you'd be hard pressed to hear the difference in an amp that's only used at <150Hz

Roscoe

[Stuart Polansky]

Then, the mod is to pull the pots from the power amps and replace them with LED gain sets!!!!

I think you'd be hard pressed to hear the difference in an amp that's only used at <150Hz

Roscoe

He has one in his HF amp.

Trouble is, that's a high Z input and Lightspeed is notoriously low Z (~7k). But if he's driving it with a SS DAC, should be no sweat.

[Jim G]

Nice of you to offer help, Stuart. If it doesn't work out for your schedule, Dhar lives very close to Dave B and Tom P. Don't mean to volunteer them, just sayin'.

He is also a great speaker builder. We'll have to work on him to show his skills at future CAPFESTs.

Jim