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Adding a Pre Out to a Luxman R-1050

ScooterMcTav

ScooterMcTav

I know less than I think
Morning All,

I currently own a Luxman R-1050 and truly enjoy the sound from it. However, I have also been presented with an opportunity to get my hands on a Jolida JD-302BRC, which although an integrated, has no phono input, and overall limited inputs.

So my thoughts were to use my R-1050 as a pre feeding the Jolida in bypass mode, allowing me to hook up 2 TTs, and all my other assorted gear.

Unfortunately, the R-1070 comes with pre-outs, not the R-1050, so I'm left with:

- Using the headphone jack, through a 1/4" to RCA adapter for a pre out (pretty cheezy)
- Adding in a set of RCAs for a pre out

My thoughts were that hooking up a set of RCAs should be pretty easy - locate the wires where the preamp sends signal to the power amp, and pigtail off a set of wires to a new set of RCAs on the ample real estate on the rear of the receiver.

Anyone else done something like this, and if so, the pros, cons, and opinion on the relative ease of the job would be appreciated.
 
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You should be able to add main in/pre out jacks. It would just be a matter of locating the wires and mounting some RCA jacks. Check out the Rean NYS367 jacks on mouser.

Using the headphone out wouldn't be a good option. The signal still runs through the power amp, it isn't a pre out.
 
While you are figuring this out, run a set of RCAs from the Rec Out on the Luxman to an input on the integrated and enjoy the two phono inputs and the tuner section of the Luxman without the tone, volume, balance controls or the filters and such on the receiver.
 
Raccoon1400 said:
You should be able to add main in/pre out jacks. It would just be a matter of locating the wires and mounting some RCA jacks. Check out the Rean NYS367 jacks on mouser.

Using the headphone out wouldn't be a good option. The signal still runs through the power amp, it isn't a pre out.
Click to expand...

This is an interesting observation, and one I struggled with when looking at this method. If the headphone amp section is basically a variable line-level output with a voltage of between 0mV to 1.1 Volts or thereabouts, this makes it somewhat hotter than vintage tape inputs, but less hot than the standard CD player, does it not? Although an inelegant solution, it struck me as being at least theoretically close to a pre out, especially if the headphone jack was being fed a unamplified preamp output.

Blue Shadow said:
While you are figuring this out, run a set of RCAs from the Rec Out on the Luxman to an input on the integrated and enjoy the two phono inputs and the tuner section of the Luxman without the tone, volume, balance controls or the filters and such on the receiver.
Click to expand...

This thought crossed my mind as well, to use one of the tape outs into one of the inputs on the JoLida. One of my challenges I do have though is an acoustically difficult room, and therefore occasional use of some tone inputs is necessary. However, I guess I could always insert an EQ inline between the tape out and the source in on the JoLida if I found some tone control necessary. Not sure I like this solution much either.

Regardless, I do have some donor units around I could grab the RCA jacks off of if I needed to, though I do also have a Rotel RX-600A that could pinch in as a pre if needed (it does have pre-outs). However, its dynamic range, though good, lacks the clear high-end extension and bass fullness of the Luxman.
 
To use the EQ, put it on tape 2 of the luxman and use the dubbing 2 to 1 to get EQ into the luxman tape 1 output to the integrated. Again all while looking over the schematic of the R-1050 to find where the preamp signal can be stolen and jacked on the back of the receiver.
 
SMT: Did you already check the service manual (or the innards), whether your Luxman actually sports a dedicated headphone-amp section? Because more usually in stereo receivers and integrated amps the headphone out will rather just be fed by the power-amp section through resistors to reduce the output level. In that case you might as well build yourself a custom voltage divider adaptor (or adaptor cable) for the speaker outs, so you needn't occupy the headphone out...

Greetings from Munich!

Manfred / lini
 
Dust off the Sherlock Holmes hat ... If you can track down which board is the preamp section, you should be able to locate shielded line level cables from that going to the amp section. Usually easy enough to spot and test. Something similar to these ...

f2634-pinning-02.jpg


From there, repurpose a set of RCA's on the back panel that you're not currently using. Add a Y cable to those, and you get the best of both worlds, with both the pre out AND/OR still using the built in amps.
 
Thanks for the replies all, again. Manfred, nice to see you here as well - I find your advice on VE always of value. Reading the schematic (service manual on HFE) I get a bt lost mapping out where the headphone out is coming from. Been about 31 years since I last drew a schematic, and it was probably for dimming a lightbulb. That being said, it can be seen that the headphone jack does come off of the power amp board; I just cannot quite ascertain how much it goes through between it and the preamp.

Blue Shadow, for yesterday, I tried the "phono 1/tape out" system, and found I'm going to need some gain on my phono stage. Whereas I was getting comfortable levels of sound via other hotter sources, I needed to use between 3/5ths and 2/3rds of the volume control to get the volume to reasonable on the Jolida. Although I realize that using more volume control isn't inherently bad, using too much volume control compounded by inattentive users (read: every other member of my family) may cause damage the one time I forget to bank down the volume and somebody wishes to listen to a different source. FWIW, this was with a Grado Green cartridge with a reasonable 5mV output.

sKiZo, I hope that is how obvious the wiring is on the amp board from the preamp - that would make my life much easier.....I'm guessing there would be no unwanted consequences from pigtailing?

All of the above being said, I really didn't find the straight through/no tone control sound all that bad - much more balanced in this room than it was with my Soliloquys. The only complaint would have been a mid-forward, very sizzly sound that was very precise, yet somewhat fatiguing when using digital sources. It's caused me to think that the pair of Wharfedale Diamond 10.6 I have sitting in my HT might be a better pairing than the ultra-revealing (and metal tweetered) MAs.

Regardless, when I have some time this weekend, I will be looking to try everything straight through, and possibly I could use an EQ inline between my iPhone and CD if the Wharfies don't tame things down enough. Eliminating a pre-amp would certainly clean up my stereo area, then all I need to find is a decent phono pre amp with gain control. That being said, if results are still inadequate, then I'll hopefully find some easily identified wires to which I can attach a pre-out.

.....or I just go find a used amp with a phone stage and preouts.......

I'm starting to think "hobby" is too gentle a word.
 
SMT: Actually I had already tried to check the service manual for you - for both how the headphone out is implemented and a suitable spot to insert a pre-out (or pre-out/main-in loop). Problem is: My old notebook has finally become all too limited for my use - ever since the latest upgrade of the antivirus software memory consumption of that has gone up yet another 50 MB, and Firefox doesn't appear to have become any slimmer lately either, so 1 GB of RAM doesn't seem to suffice for viewing larger PDFs anymore... *sigh* Not quite sure, whether that was for your case or another recent one, but I recently even tried to give it 20 minutes, before I gave up. I've also already tried to reconfigure the antivirus (Avast - one of the last to still support WinXP) to not keep a constant "white list" of already scanned files, but that has hardly reduced the memory consumption at all.

So it seems to be about time for me to finally move on to my new notebook - and I also better should, before that's outdated again. If I'd just feel like it. *sigh* Sometimes I really wish I was 18 years again - when a new computer still was something to be excited about, and I could hardly wait to put it into operation... Nowadays to me that more like: "Oh no, yet another new computer and operating system to tame..."

Greetings from Munich!

Manfred / lini
 
Thread Revival Alert!!
I finished a complete refurb on my 1050 but haven't put it in service yet. The reason? I am still considering adding Pre-Out jacks for optional sub use (Rythmic L12) which or course, uses Line-Level inputs only. The Deck-2 Monitor Terminals would be perfect for this, as Deck-2 could be connected via the DIN port if desired.
What would this mod involve? Could the preamp-main amp circuits simply be paralleled?
Would i need to add additional components/circuitry to the new preamp output circuit?
I previously used a line level adapter connected to Speaker-B but that's not the mission anymore. Speaker choices are more important.
TIA, as always..
 
Whenever I needed an extra set of pre-outs, I just used a pair of splitter cables. Ow you have two pre-outs from one preamp, or preamp section of an integrated amp with pre-outs. Most preamps have plenty of gain to handle two sets of pre-outs. The preamp in my main system has two sets of pre-outs. The second set is just wired to the first set of pre-out jacks.
I have two stereo tube amps, an a pair of tube mono blocks. I have a set of splitter cables connected to one of the set of pre-outs. I only use one stetero amp or the mono blocks at a time. I could use two amps if I wanted, I probably wouldn't use all three ever though.
I had an integrated amp that didn't have pre-out Main in jacks so I added them. I ran the shielded cables from the preamp section to added pre-out jacks, and added shielded cable from the I put of the amp section to an added set of main in jacks. I used jumpers on the jacks to connect the preamp and amp sections. If I wanted to use the amp as a preamp, I just pulled the jumpers and connected a power amp to the pre-out jacks.
 
Just a word of warning about attempting to add preamp outputs to an amp or receiver that didn't have them. Not all preamp sections are capable of driving an outboard power amp, their output impedance might be too high. Which also means that the amp built into it would have a very high input impedance, and not be compatible with an outboard preamp. Which may be part of the reason main in/pre out jacks weren't included in the first place.
Also, some of these units don't have separate amp/preamp sections and some even integrate the tone controls into the NFB loop of the amplifier proper.
I don't know if that is the case with this particular unit. It's just something to be aware of.
 
tarior said:
Just a word of warning about attempting to add preamp outputs to an amp or receiver that didn't have them. Not all preamp sections are capable of driving an outboard power amp, their output impedance might be too high. Which also means that the amp built into it would have a very high input impedance, and not be compatible with an outboard preamp. Which may be part of the reason main in/pre out jacks weren't included in the first place.
Also, some of these units don't have separate amp/preamp sections and some even integrate the tone controls into the NFB loop of the amplifier proper.
I don't know if that is the case with this particular unit. It's just something to be aware of.
Click to expand...
Yup. That's why using soitte4 cables if possible is a non invasive way to do it. If it can't properly drive the amp you just remove the cables.
 
One can always add an opamp buffer with a gain of between one and two, though not everyone will want to do that.
 
Thanks yall for the advice and input. meanwhile, think i'll hook up the Lux without the mods and continue to overthink the situation.
 
tarior said:
One can always add an opamp buffer with a gain of between one and two, though not everyone will want to do that.
Click to expand...
You just reminded me that I need to get back to making a 4580 work in a KR-710.

....need to rethink epoxying it to the double rca jack......
 
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