The cheapest I've heard of was from Emotiva. Going by reviews and forum comments, they suffered from some bugs. Pioneer made AVRs with preamp outputs, but used receivers are liable to have problems, so that's a different gamble. Maybe it's feasible to modify an AVR and add preamp outputs; a used one with a blown amp channel ought to be dirt cheap. But, if they've gone to an all-digital signal path, you might just have a door-stop.
So, the cheapest safe bet is to embrace the dark side and get a new AVR with a warranty on sale. Or if you really want a pre/pro, hunt for older models that don't do 3D or 4k or Atmos. High-end dealers and installers may have trade-ins.
So, the cheapest safe bet is to embrace the dark side and get a new AVR with a warranty on sale. Or if you really want a pre/pro, hunt for older models that don't do 3D or 4k or Atmos. High-end dealers and installers may have trade-ins.
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I think it's a shame that preamp outs on receivers went away. With the race-to-the bottom pricing mindset these days, it seems like any feature that falls beneath some high threshold of popularity is immediately deleted.
I have discovered that a lower-end receiver with a mediocre power amp section can have a surprisingly nice-sounding front end when connected to some decent amplification. I've modified a couple of inexpensive Yamaha AVRs for preamp outs, and have been very pleased with the results. If you're into modding your gear, all it really takes is a free afternoon and a bit of shielded cable (and ideally a schematic & board diagram). You can repurpose some unused input jacks for outputs. I also disconnected & grounded the inputs to the internal power amp channels.
-- Jim
I have discovered that a lower-end receiver with a mediocre power amp section can have a surprisingly nice-sounding front end when connected to some decent amplification. I've modified a couple of inexpensive Yamaha AVRs for preamp outs, and have been very pleased with the results. If you're into modding your gear, all it really takes is a free afternoon and a bit of shielded cable (and ideally a schematic & board diagram). You can repurpose some unused input jacks for outputs. I also disconnected & grounded the inputs to the internal power amp channels.
-- Jim
@Dangus: Emotiva I have looked into, also into a sherbourne. I'm in no hurry, I would wait for the technology to get better. I have a few HDMI avr's that have had issues. I'll wait it out if needed.
@Jim: Lower end receiver sounds like a good idea, but have any specific make/model numbers ?
Cool.
Srinath.
@Jim: Lower end receiver sounds like a good idea, but have any specific make/model numbers ?
Cool.
Srinath.
The AVRs I've modified were both Yamahas, model HTR-4065 and RX-V573 - essentially 5.1 and 7.1 versions of the same model. I had access to service manuals for both, as I was working for a Yamaha dealer at the time. Not sure how hard it would be to obtain this info as a "civilian" - different manufacturers have different policies about supplying service materials & parts to end users. Still, it's not impossible to complete a project like this without a road map; just more time-consuming and error-prone.
A couple of things I forgot to mention - I was lucky with my Yamahas to find a point to pick off the signal that was directly before the power amp input, but directly after the simple shunt muting circuit for each channel. This is an important feature.
Also, remember that this point in the circuit isn't necessarily designed to be a connection to the outside world. For example, I was basically taking the signal right out of the multichannel volume control IC, with the shunt muting transistor in parallel and a low-value resistor or two in series. The block diagram for this chip indicated buffer stages at each analog output, but I had no actual specs for them - they were just little triangles on the page. I never used cables longer than 2 or 3 feet to connect to the power amps, and all my frequency response measurements remained ruler-flat; but with longer cables, your mileage may vary.
Good luck,
-- Jim
A couple of things I forgot to mention - I was lucky with my Yamahas to find a point to pick off the signal that was directly before the power amp input, but directly after the simple shunt muting circuit for each channel. This is an important feature.
Also, remember that this point in the circuit isn't necessarily designed to be a connection to the outside world. For example, I was basically taking the signal right out of the multichannel volume control IC, with the shunt muting transistor in parallel and a low-value resistor or two in series. The block diagram for this chip indicated buffer stages at each analog output, but I had no actual specs for them - they were just little triangles on the page. I never used cables longer than 2 or 3 feet to connect to the power amps, and all my frequency response measurements remained ruler-flat; but with longer cables, your mileage may vary.
Good luck,
-- Jim
There is also the miniDSP route https://www.minidsp.com/products/ht-series/nanoavr-hda
But still needs an 8 channel pre-amp. Most newer blu-ray output LPCM.
But still needs an 8 channel pre-amp. Most newer blu-ray output LPCM.
Thanks Jim.
There is an RX-V673 on my local CL, these Yamaha HDMI amps are not too rare, I should be able to find them pretty easy over the next few months.
@Dangus: That Marantz series does have a great rap, I also have seen em on my local CL for ~500. I'll have to try the Yamaha modification idea first though, I'm more of a tinkerer than a spender, even if it means not saving much $$$ or getting a better product.
@Billshruv: Yea I looked @ the minidsp earlier, 8ch preamp - well, I'm trying to get one that also does HDMI input processing.
@Rif: I think I'd probably go the Yamaha direction, but outlaw is very very cool just to say I have an outlaw anything. LOL.
Cool.
Srinath.
There is an RX-V673 on my local CL, these Yamaha HDMI amps are not too rare, I should be able to find them pretty easy over the next few months.
@Dangus: That Marantz series does have a great rap, I also have seen em on my local CL for ~500. I'll have to try the Yamaha modification idea first though, I'm more of a tinkerer than a spender, even if it means not saving much $$$ or getting a better product.
@Billshruv: Yea I looked @ the minidsp earlier, 8ch preamp - well, I'm trying to get one that also does HDMI input processing.
@Rif: I think I'd probably go the Yamaha direction, but outlaw is very very cool just to say I have an outlaw anything. LOL.
Cool.
Srinath.
You don't really need a preamp to use nanoAVR-HDA. Here's my recent upgrade story which deals with that (coincidentally, Outlaw Audio is also involved).
Epilogue: The tweeters have been replaced.
-- Jim
Yeah, one of mine was open-box from somewhere, the other was Ebay; they both worked nicely.
True, that's one thing they won't do - LPCM only for them. Hasn't been a problem for me using an HTPC, it'll play everything except SACDs. (Don't get me started on those damn things.
)Outlaw made the power amps I'm using, model 7075. I have 2 of them, and I'm mostly very happy with them except for one issue I just finished dealing with. One of them developed a bunch of defective transistors in the input differential pairs, which caused several channels to become noisy and DC-offset-y, one by one over the course of a year or two. Found suitable current-production replacements at Digi-Key, replaced them all a couple of weeks ago, and she's good as new. The other one shows no sign of this problem.
-- Jim
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You don't really need a preamp to use nanoAVR-HDA. Here's my recent upgrade story which deals with that (coincidentally, Outlaw Audio is also involved).
Epilogue: The tweeters have been replaced.
-- Jim
Guess a series cap would not have saved you there.
I just like a knob to twiddle. Fnarr fnarr
Guess a series cap would not have saved you there.
Hi Bill, first of all kudos for reading that far - I tend to rattle on.
Second, and I apologize for thread creep, but do you or anyone else here know of a way to "subtract" a pole from an even order filter (LR48 in this case), in order to replace it with a series cap? I can't see how this is possible, but me too dumb to know for sure.
I know about the other method of placing the cap reactance a decade or so down from crossover, but man, I really doubt that would've been effective enough protection against the type of big nasty scary noise that happened back there.
When you're right, you're right.
-- Jim
I had to find out what killed them!
I go for the big cap a decade down approach, but that would still let enough through to damage things. It's my biggest worry with DSP based crossovers without something with a handy mute switch in the way.
Maybe I need one of those big red kill buttons on the wall behind me
I go for the big cap a decade down approach, but that would still let enough through to damage things. It's my biggest worry with DSP based crossovers without something with a handy mute switch in the way.
Maybe I need one of those big red kill buttons on the wall behind me
This is a legitimate worry, as I found out the hard way.
My original plan was to replace the dual Yamaha AVRs with the analog out HDA upgrades to the nanoAVRs, then build a big 12- or 16 channel analog volume control, probably using a bunch of PGA2311s. When I discovered how well the IR remotes were tracking between the 2 miniDSP units, the analog master volume box went on the back burner. But since this recent mishap I'm back to looking at Plan A, perhaps with some extra protect-mute scheme included. I do miss having that analog attenuation "cushion" in there at the very least.
-- Jim
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