[pbzepplin]

I have recently built a set of XLS Encores and am excited to get into the hobby. They are far superior to previous speakers I have heard and I am excited to start to build out a system to get the most out of the speakers. I have watched a few of the GR Research youtube videos and heard about a chip amp DIY solution to get really good sound from the speakers. I found the thread on the 7297 but it seems the boards may not be available to build this AMP out. Any ideas or recommendations on a DIY solution for an AMP to get the most out of the speakers?

Thanks,

Steve

[richidoo]

Check out Neurochrome Modulus86 for 60w@4R
If you need more power, Purifi 400. Neurochrome has kit coming and Ghent has a kit. 

[mkrawcz]

Normally I would second the Neurochrome Mod86, however the LM3886 chip is impossible to get right now and they won’t be available for at least a year. I recently got some Purifi 400 based amps and they are incredible. So that’s my recommendation. You could go with the pre made Neurochrome modules, but I have them all and my Purifi amps are simply better across the board. The other diy option would be the Orchard Audio Starkrimson GaN modules which may be even better than the Purifi modules. I have some arriving in a couple days so I am about to find out.

[pbzepplin]

Thanks for the quick responses. I watched the assembly video on the mod86 looks interesting. Especially since you can populate the board from scratch definitely looks like the most DIY aspects. Although that is a little troubling on chip availability which as been hard across the board lately. I have had the Purifi on the top of the list based on how many positive reviews are in the user community. I have heard the input stage can make a huge difference on these. Does anyone know if its true that you get a cleaner signal with reduced gain on the input stage. I doubt I will need all of the power the purifi can deliver with stock gain. My listening position is 8-10ft from the speakers and I am not one to crank the volume to 11.


The orchard really does look interesting also. I have had a chance to play with some other gallium nitride based electronics at work and they are pretty unique. I would be really interested to hear your thoughts once you get a chance to A/B them against the Purifi

[Jaytor]

I agree that the Purifi amps are nicer than the LM3886 based Neurochrome amps (at least my Modulus-286 monoblocks). I've tried a few different input buffers on the Purifis and the Neurochrome buffers are quite nice - very detailed and transparent sounding with a decent sound stage. The VTV tube input buffers with a good NOS 6DJ8 tube and Weiss discrete op amps sounds a bit smoother with a deeper sound stage, but this buffer is quite a bit more expensive than the Neurochrome buffers. I'm currently using a stereo Purifi amp with Neurochrome buffers on my NX-Studios.

I was on the Starkrimson amplifier tour set up on the Steve Hoffman forum and got to compare the amp with my Purifi monoblocks (with tube buffers) and my 300B SET Amps. I was using them on my NX-Oticas. I had a couple of audiophile friends over for the comparison. None of us thought the Starkrimson was a good match with my system. The sound was veiled with a recessed soundstage. We actually thought that there might be something wrong with the amp given the positive reviews from others.

Coincidentally, the next person on the tour also has NX-Oticas and felt the same way about the amp. But subsequent folks on the tour (same physical amp) thought it was great and some ordered their own. So system synergy is key here, and the NX-Otica is not the same speaker as the XLS Encore.

[OSIB16]

The LM3886 chip when used correctly; in a decent power amplifier design is incredibly transparent sounding (equivalent to a £4000 Krell). I recently finished my LM3886 monoblocks which I built from scratch, using mini aluminium PC cabinets, and ‘point to point wiring’ with super exotic parts like MIFLEX KPCU-3 Films capacitors, Elna Silmic II electrolytic capacitors, UPOCC copper wiring 99.9999% purity, DUELUND cotton oil stranded wire, etc etc. The end result is stunning transparency, ocean deep bass, super hear through midrange. But the best news is that I have solved the common problem of LM3886 chip overheating. My finished monoblocks run as ‘cool as a cucumber’. They hardly get warm, no matter how hard you push them. Here’s a link to a detailed explanation (with photos) to show how they were built…

https://www.audiocircle.com/index.php?topic=184093.0

[OSIB16]

Photos…

[poseidonsvoice]

I was on the Starkrimson amplifier tour set up on the Steve Hoffman forum and got to compare the amp with my Purifi monoblocks (with tube buffers) and my 300B SET Amps. I was using them on my NX-Oticas. I had a couple of audiophile friends over for the comparison. None of us thought the Starkrimson was a good match with my system. The sound was veiled with a recessed soundstage. We actually thought that there might be something wrong with the amp given the positive reviews from others.

Actually, I doubt there was anything wrong with your Starkrimsons. It's just that everything is based on a point of comparison. So the Starkrimsons are more laid back and less vivid in the upper midrange/treble along with a broad soundstage. It won't get in your face. The Purifi is definitely more vivid and even more so when you start rolling tube buffers and the like.

Some listeners will like one type based on their speakers and music material. Others will like the other type. The point is...there really isn't a best. It's a journey. Which is why I have 3 Class A/AB builds I will be building into the next year - all with linear supplies. Cause it's fun.

One amplifier that is not mentioned here but isn't DIY is the Denafrips Thallos. It's Class A/AB and sounds quite excellent. We listened to it versus the Purifi and it had all the purity of the bass/bass detail along with the midrange and upper midrange of tube designs as well as single ended Class A solid state designs (like my Alpha Nirvana designed by Hugh Dean).

Class AB solid state designs is a whole nuther world. You've got VFA design and CFA design topologies. You've got ones that use BJT's as outputs or Vertical MOSFETS as outputs. And finally you have Lateral MOSFETS as outputs (such as Exicon distributed by Profusion). Within VFA design (about 95% of solid state designs out there) and CFA design topologies there is a smorgasbord of input stage designs whether JFET or BJT along with choices of Miller compensation (TMC) or TPC compensation schemes. 

Good luck in your builds!

Best,
Anand.

[VinceT]

I have recently built a set of XLS Encores and am excited to get into the hobby. They are far superior to previous speakers I have heard and I am excited to start to build out a system to get the most out of the speakers. I have watched a few of the GR Research youtube videos and heard about a chip amp DIY solution to get really good sound from the speakers. I found the thread on the 7297 but it seems the boards may not be available to build this AMP out. Any ideas or recommendations on a DIY solution for an AMP to get the most out of the speakers?

Thanks,

Steve

I really like my Encores, they took a while to really break in but once they did they punch above their weight. I have tried mine with many different amps... tube and SS 35-150 watts. IMO they sound the best fed some power. I would recommend 100+ watts. Not that they don't sound great with lower wattage amps, but they come alive with some juice.

[mkrawcz]

I was on the Starkrimson amplifier tour set up on the Steve Hoffman forum and got to compare the amp with my Purifi monoblocks (with tube buffers) and my 300B SET Amps. I was using them on my NX-Oticas. I had a couple of audiophile friends over for the comparison. None of us thought the Starkrimson was a good match with my system. The sound was veiled with a recessed soundstage. We actually thought that there might be something wrong with the amp given the positive reviews from others.

Coincidentally, the next person on the tour also has NX-Oticas and felt the same way about the amp. But subsequent folks on the tour (same physical amp) thought it was great and some ordered their own. So system synergy is key here, and the NX-Otica is not the same speaker as the XLS Encore.

I think part of it is the Starkrimsons need a potent preamp with a very low output impedance. They only have 16.5db of gain. I bet a tube preamp won’t work very well with them. I have a Benchmark la4 that is ideal so it will be interesting. I will report tomorrow when I get them how they sound on my NX Oticas compared to the VTV Purifis.

[poseidonsvoice]

I think part of it is the Starkrimsons need a potent preamp with a very low output impedance. They only have 16.5db of gain. I bet a tube preamp won’t work very well with them. I have a Benchmark la4 that is ideal so it will be interesting. I will report tomorrow when I get them how they sound on my NX Oticas compared to the VTV Purifis.

The input impedance of the Starkrimson is 47K ohms, so not that low to be honest (the original design used to be 10K but not anymore). If you have a preamp with 2K or less output impedance, you should be fine. The 16.8dB does need to be accounted for in the overall setup of your system. So if you are used to listening to an amp that is 26dB of overall gain, when you insert a 17dB one, you’ll suddenly feel as things got quiet. All you have to do is turn up the volume on your pre or your dac. Easily accounted for. I know some fellas who integrated a Neurochrome Universal Buffer board with their Starkrimson DIY builds and made it to 26dB that they are used to. Also easy (since we are talking about DIY time which is free  )

I use my Holo Audio dac direct to the Starkrimson and it works just fine. In fact, I don’t use analog preamps anymore since moving to HQPlayer/Roon combination (all music is at DSD512 and I use the integral VC from HQPlayer). I don’t like to add too many coloration devices to the system. And that’s what an analog preamp has become when you think of the analog stages, the interconnect cables and the power cable. My coloration comes from the amplifier I am fooling around with! Horses for courses though, I know plenty of fellas that feel that preamps are the ‘heart’ of their audio system. To me and in a digital setup, it has become unnecessary. My previous pre was an all silver Slagleformer based pre. The HQPlayer/Roon combo with DSD512 beat it, but it wasn’t a slam dunk. Just better, clearer and more direct. All this worked out cause my main speakers are 96dB sensitive. Systems with speakers that are lower in sensitivity will either need a preamp or an amp with a large amount of gain (i.e. 26dB or more).

Best,
Anand.

[pbzepplin]

I clearly have a lot to learn. I understand how the gain impacts the levels, but can someone explain how the input impedance factors into the quality of sound transmission. I am sorry if this is a basic question. Happy to go read up on it also if someone can point me to a good reference.

OSIB16. That is a really cool design! Love the custom mods of the AMP.

Steve

[mkrawcz]

The input impedance of the Starkrimson is 47K ohms, so not that low to be honest (the original design used to be 10K but not anymore). If you have a preamp with 2K or less output impedance, you should be fine. The 16.8dB does need to be accounted for in the overall setup of your system. So if you are used to listening to an amp that is 26dB of overall gain, when you insert a 17dB one, you’ll suddenly feel as things got quiet. All you have to do is turn up the volume on your pre or your dac. Easily accounted for. I know some fellas who integrated a Neurochrome Universal Buffer board with their Starkrimson DIY builds and made it to 26dB that they are used to. Also easy (since we are talking about DIY time which is free  )

I use my Holo Audio dac direct to the Starkrimson and it works just fine. In fact, I don’t use analog preamps anymore since moving to HQPlayer/Roon combination (all music is at DSD512 and I use the integral VC from HQPlayer). I don’t like to add too many coloration devices to the system. And that’s what an analog preamp has become when you think of the analog stages, the interconnect cables and the power cable. My coloration comes from the amplifier I am fooling around with! Horses for courses though, I know plenty of fellas that feel that preamps are the ‘heart’ of their audio system. To me and in a digital setup, it has become unnecessary. My previous pre was an all silver Slagleformer based pre. The HQPlayer/Roon combo with DSD512 beat it, but it wasn’t a slam dunk. Just better, clearer and more direct. All this worked out cause my main speakers are 96dB sensitive. Systems with speakers that are lower in sensitivity will either need a preamp or an amp with a large amount of gain (i.e. 26dB or more).

Best,
Anand.

The Benchmark La4 preamp is the cleanest, lowest distortion, highest bandwidth preamp in the world. It’s the closest thing to a straight wire with gain so not worried about that aspect of it. I have a Holo Spring 3 KTE with preamp and find that using it alone does not yield as big a soundstage as when a good preamp is in the chain such as the LA4 or the BHK preamp. For amp gain, I’ve always found that very low gain amps sound softer even when level matching the volume. It’s clearly audible through my AHB2 when switching to the different gain settings and getting the amp back to the same volume. There is a loss of life and dynamics to the amp. This was even written about on Audioholics where they showed that lowering the gain of the amp causes a loss of dynamic headroom. That affects transient response.

[Jaytor]

I can't remember which preamp I was using at the time, but both of my preamps have an output impedance of less than 50 ohms per leg (fully balanced). So this wasn't the issue. My 300B amps actually has the lowest input impedance when using the balanced inputs (10K ohms) and those sounded fabulous when we switched to them in the same listening session.

Something about the way the Starkrimson behaved with the NX-Oticas - just weird.

Hope you have better success.

[poseidonsvoice]

The Benchmark La4 preamp is the cleanest, lowest distortion, highest bandwidth preamp in the world. It’s the closest thing to a straight wire with gain so not worried about that aspect of it. I have a Holo Spring 3 KTE with preamp and find that using it alone does not yield as big a soundstage as when a good preamp is in the chain such as the LA4 or the BHK preamp. For amp gain, I’ve always found that very low gain amps sound softer even when level matching the volume. It’s clearly audible through my AHB2 when switching to the different gain settings and getting the amp back to the same volume. There is a loss of life and dynamics to the amp. This was even written about on Audioholics where they showed that lowering the gain of the amp causes a loss of dynamic headroom. That affects transient response.

As long as you’re happy! Enjoy! The Benchmark LA4 is an excellent piece. If I wasn’t just a diy aholic, I would probably own it. My buddy has NX Otica’s and he uses a pre he built using Tom’s Universal Buffer Boards. Works extremely well 

Recently, I have gravitated towards 26dB gain amplifiers since I am using HQPlayer/Roon @ DSD512 which drops my Holo Audio May dac’s output voltage to 2.8V RMS (1/2 of the PCM output voltage which is 5.6V RMS). I couldn’t hit my 105dB peaks!! 

Best,
Anand.

[poseidonsvoice]

I clearly have a lot to learn. I understand how the gain impacts the levels, but can someone explain how the input impedance factors into the quality of sound transmission. I am sorry if this is a basic question. Happy to go read up on it also if someone can point me to a good reference.

OSIB16. That is a really cool design! Love the custom mods of the AMP.

Steve

Just keep it simple. The output impedance of your source (cd player, dac, preamp, phonostage, etc…) should be at least 10X’s lower than the input impedance of what it is feeding (i.e. amplifier). So an amp with a 10K input impedance should be driven by a source that is 1K ohms or lower. If you use a source that is 5K ohms for example, you might suffer excessive high frequency loss and the performance sounds ‘dull’ in the top end.

Best,
Anand.

[mkrawcz]

As long as you’re happy! Enjoy! The Benchmark LA4 is an excellent piece. If I wasn’t just a diy aholic, I would probably own it. My buddy has NX Otica’s and he uses a pre he built using Tom’s Universal Buffer Boards. Works extremely well 

Recently, I have gravitated towards 26dB gain amplifiers since I am using HQPlayer/Roon @ DSD512 which drops my Holo Audio May dac’s output voltage to 2.8V RMS (1/2 of the PCM output voltage which is 5.6V RMS). I couldn’t hit my 105dB peaks!! 

Best,
Anand.

I used the Neurochrome universal buffer to convert my Folsom 7293 to balanced and the results are really good. A diy preamp using them is on my list of projects.

[OSIB16]

OSIB16. That is a really cool design! Love the custom mods of the AMP.

Steve

Thanks. I just stuck with the original crossover layout, but simplified it and added proper grounding. The LM3886 when done right is a tremendously musical piece of kit.

[mkrawcz]

So I’m listening to the Orchard Audio Starkrimson monoblocks. I will give them some time and hours, but at this point they definitely lack the refinement of my VTV Purifi amps. With the Purifis I think “OMG, she is singing 10 feet in front of me in my room”. With the Starkrimsons, they sound like they have more detail, but something is lost and there is less of a real 3D presentation in between the speakers, it’s flatter. Now, that may not be the fault of the modules. It could be that the Weiss opamps on the input buffer of the purifis are just really good. Peoples impressions may vary based on speakers, but the NX-Oticas “separate the men from the boys” when it comes to amplifiers, preamps, and dacs. You know pretty quickly when something is missing that you had before.

[poseidonsvoice]

So I’m listening to the Orchard Audio Starkrimson monoblocks. I will give them some time and hours, but at this point they definitely lack the refinement of my VTV Purifi amps. With the Purifis I think “OMG, she is singing 10 feet in front of me in my room”. With the Starkrimsons, they sound like they have more detail, but something is lost and there is less of a real 3D presentation in between the speakers, it’s flatter. Now, that may not be the fault of the modules. It could be that the Weiss opamps on the input buffer of the purifis are just really good. Peoples impressions may vary based on speakers, but the NX-Oticas “separate the men from the boys” when it comes to amplifiers, preamps, and dacs. You know pretty quickly when something is missing that you had before.

Thanks for the report! I suspected as much as I have heard the Purifi’s (in other systems) and they do have a certain realism to them. Are the Starkrimsons diy ones you built or are they the stock Orchard Audio versions?

Best,
Anand.