Another HQMC Phono Stage build

[sann]

I had been planning to build this special phono stage for my LOMC cart (Denon DL-103) for sometime now, I was thinking that this would be really special if it performs somewhat equal if not better than Pearl II and would eliminated the need to buy a SUT, and I would be able to use my ACA with my LOMC cart, the cost to put it together was half than the cost of any entry level SUT, so I decided to give it a try.

I housed it in my Pass B1 cab.

Here is the closeup:

Loaded at 100ohm and gain resistance set to 800ohm

Now coming to the sound quality.
This phone stage is a top notch design, very detailed, refined, with superb bass, the vocals are slightly pushed back and the instruments tend to come a little forward, which is according to my listening taste.

The top end is little grainy, but I read that it is due to the Russian PETP caps, and they have a burn in period of over 100 hours after that the bass definition improves further and the top end becomes smooth.

I am surprised to find what I had been missing before I found this special match for my DL-103.

Thanks Sachin for providing the pre soldered kit, knowing that I have been keeping busy. You are a gem.

Happy Listening
-sann

 

[reubensm]

what a superb build, congrats!!

enjoy the music!!

 

[sachu888]

Nice build Sandeep. Those Russian caps take long time to break in. I have experienced same think in my B1. Graininess could also be due to impending setting. I feel 100 Ohm is low for DL 103.
Try different impedance settings.

Regards
Sachin

 

[sann]

Thanks Sachin, I tried 125ohm today morning, and yes it made the HF smoother. I will keep it at 125 and let the caps burn in. And later on would again give 100ohm a try. Enjoying the unheard details now.

 

[Record Player]

This is simply fantastic. Already heard good views from the FMs here.

Congrats!

 

[jls001]

@sann: do favour us with a Hypnotoad v/s Pearl 2 comparo

 

[sann]

Joshua, you have given a difficult task to me, I am trying to put together my impression of the two great phono stages, according to how they sounded to my ears during the last few days.

1. Gain - Pearl2 - vol pot resides between 12-2 (doesnt make much difference beyond 2 also) HQPCPS - 10 O'clock is loud enough (at 875ohm we can go till 2K)This eliminates the need of using a SUT
   
   
2. Cost - If we want the same gain from Pearl2 we will need to use the SUT, and that would take the Pearl2 setup cost to around 5 times more than the HQMCPS
   
   
3. Design - Pearl2 is fully discrete BL-170 amplification and HQMCPS is opamp based, I suffered from a lot of restless opamp rolling symptoms when I was using CNC phono, switching over to Pearl2 eliminated that nesting ground, not I am again using opamps but believe me, the thought of rolling has not occurred to me even once so far. HQPCPS provide trimmers for gain and input loading, though we can use input loading trimmers with Pearl2 also.
   
   
4. Rack Space and form factor - Pearl 2 needs two full sized cabinets, one is dedicated for power supply, HQMCPS can fit into the preamp cab eliminating the need for new power supply / cabling and helps keeping the signal path shorter, though this introduces the risk of hum issues as the high gain phono circuit is close to the power supply.
   
   
5. Background noise(hum/hiss) - Pearl2 is dead silent believe me, I struggle to hear the hum at full volume even when I placed my ears next to the speaker, in HQMCPS the hum is audible even from a distance if the vol pot it turned to around 12'o clock position when the needle is not resting on the groove, however it is not at the levels at which is started interfering with the music, and I can live with it, I will request Raghu to make a beautiful small cab for it with wooden face plate.
   
   
6. Bass - Yes it needs a special mention, with HQMCPS the bass goes to such levels which I had never experienced in my system before,
   
   
7. Rresolution/Details - Pearl2 has a warm sound signature, though I have not heard any tube phono however I have read that it sounds more like that. Now, if I compare it against HQMCPS it tends to loose out the details in upper mid and HF range.
   
   
8. Mid Range (vocals)- With Peral2 vocals sound thick, lush and bold and slightly pushed forward, HQMCPS renders them slightly thinner and puts them behind the instruments, which as I mentioned earlier I tend to like more.
   
   
9. Lower Mid Range - Even with the old hindi mono pressings, Tabla is prominently placed with the song, which was sorely missed earlier. According to my listening taste, I like the lower mid range notes distinctly present through the song in the lower mid range HQMCPS excels, I like the bass guitar notes in this range.
   
   
10. Upper Mid and High Frequency - After listening to HQMCPS I feel that Pearl2 rolls off the high frequency and sounds a bit on the warmer side, and I think this leads to loss of details in the upper mid and HF range. strings based instruments sounds very energetic with HQPCPS.
    
    
11. Musicality - Both the phono stages are a pleasure to listen to and can be enjoyed over long listening sessions without any listening fatigue, HQMCPS seems to deliver more music though.
    
    
12. MM and MC cart compatibility - Pearl2 can be used with both MM and MC cartridges, however HQMCPS is only designed for LOMC carts.
    
    
13. Pace, Dynamism and Attack - I tried playing fast music passages and HQPCPS excels in all three departments.
    
    
14. Surface Noise - Though this depends on a lot of other factors, however I did not notice any major difference here.

As on date I am inclined towards using HQMCPS for LOMC cartridges, I will change the loading of pearl2 from 100ohm to 47k and write a review with my AT-150ea MM cartridge.


~Happy Listening~
-sann'

 

[Record Player]

This is quite detailed Sann. Many thanks. The HQMCPS seems a winner considering a lot of points mentioned above.

 

[jls001]

Thanks, sann for such a detailed comparison. I have been meaning to pen down a comparison between the two but I find it difficult to do a meaningful one as I run the two phono stages on completely different turntables. The Hypnotoad is a real winner in my books given the money spent and the much simpler build.

 

[sachu888]

Excellent review, Sandeep. The faint hum is only because of very gain of HQMCPS.You have housed it in a same cab with transformer and power supply.It should go away completely,once you keep it in a separate metal cab.

Regards
Sachin

 

[dillihifi]

I built a Phono based Hypnotoad's design using the parts supplied by Sachin and troubleshooted by Omishra. I use this phono with the Ortofon Rhondo Red Cart and have Lyrita pre power using EL-34 based amplification. I am still powering it with two nos of 1 A, 12 V adapters like Joshua.

I am quite happy with the phono. Can you please tell me what are the major differences between my phono and the HQMC one.

@ Sachin - The phono board has stock caps will the Russian ones make any major difference and should I try them out ??

 

[jls001]

Excellent review, Sandeep. The faint hum is only because of very gain of HQMCPS.You have housed it in a same cab with transformer and power supply.It should go away completely,once you keep it in a separate metal cab.

Regards
Sachin

Sann, this probably true as I don't get any audible hum from the Hypnotoad.

 

[sachu888]

I built a Phono based Hypnotoad's design using the parts supplied by Sachin and troubleshooted by Omishra. I use this phono with the Ortofon Rhondo Red Cart and have Lyrita pre power using EL-34 based amplification. I am still powering it with two nos of 1 A, 12 V adapters like Joshua.

I am quite happy with the phono. Can you please tell me what are the major differences between my phono and the HQMC one.

@ Sachin - The phono board has stock caps will the Russian ones make any major difference and should I try them out ??

Your board is having provision for onboard power supply option. Hypnotoad have tested it with onoard power supply,but it had hum. That was the reason I have not sent you on board power supply components.He has removed power supply part in his next layout(Sann's PCB).Everything else is same,only addition of 390R resisters in place of 560R, and 220pf RIFA/WIMA small caps.
Russian caps are great.I liked it very much in my DIY B1.I have few caps on order and I will ship them to you as soon as I receive them.

Regards,
Sachin

 

[malvai]

Excellent write-up Sann! I am glad I ordered a hqmc and thanks to sachu and Joshua for helping in building it for me!!!

 

[frend2001]

Dear FMs

I've just brought home a COSMIC CO GRAM 2000 BD with MM cartridge.

I'm a total noob in case of preamp and phono stage....need you guys guidance, I can solder a bit but unaware of most of the trade jargon.....Need your help friends.

 

[sachu888]

Dear FMs

I've just brought home a COSMIC CO GRAM 2000 BD with MM cartridge.

I'm a total noob in case of preamp and phono stage....need you guys guidance, I can solder a bit but unaware of most of the trade jargon.....Need your help friends.

Could you tell us the cart no or post a pic.This is an MC phonostage and will not work with MM carts.You can build CNC phonostage for MM http://www.hifivision.com/phono-turntables/20115-batery-powered-diy-cnc-phono-stage.html

Regards,
Sachin

 

[reubensm]

Dear FMs

I've just brought home a COSMIC CO GRAM 2000 BD with MM cartridge.

I'm a total noob in case of preamp and phono stage....need you guys guidance, I can solder a bit but unaware of most of the trade jargon.....Need your help friends.

As intimading as it may sound to the first-timer, building a phonostage is perhaps one of the easiest DIY projects anyone can make a start with. All you would need is good PCB, the required components and some soldering skills. If you have the soldering skills, that's 50% of the requirements met, you can easily accquire the PCB and components if you set out to do so. You have access to detailed info on builds for Moving Magnetic, Moving Coil and even Ceramic phonostages on HFV.