Now a Soviet Era Drivers for the Mets

P.S ...The differences between early and late models of 10gdsh-1 speakers are in the different designs of a closed loop.
In the early models, it had the shape of a cap and was installed on the core of the magnetic system, and in later models it was implemented as a ring, which was already installed on the upper flange.
Since the influence of the alternating magnetic field of the voice coil on the magnetic circuit occurred not only at the height of the flange, but also along the entire length of the coil, then the compensation of this effect will be more effective with a short-circuited loop placed on the core. Also, the 10d-36k loudspeaker has another curve of the high-frequency diffuser profile.
Given the above features, it becomes clear why the early models had better detail in the upper frequency response range and are in great demand among music lovers.
 
Thanks Oleg for the detail difference between both models. You are right about the upper high frequency of this driver. It can put the best of the tweeters to shame. They are not only detailed and airy but not at all compressed. They sound liquid, organic and holographic to my ears.
 
P.S ...The differences between early and late models of 10gdsh-1 speakers are in the different designs of a closed loop.
In the early models, it had the shape of a cap and was installed on the core of the magnetic system, and in later models it was implemented as a ring, which was already installed on the upper flange.
Since the influence of the alternating magnetic field of the voice coil on the magnetic circuit occurred not only at the height of the flange, but also along the entire length of the coil, then the compensation of this effect will be more effective with a short-circuited loop placed on the core. Also, the 10d-36k loudspeaker has another curve of the high-frequency diffuser profile.
Given the above features, it becomes clear why the early models had better detail in the upper frequency response range and are in great demand among music lovers.

So, Oleg, which ones are you going to send to me, early model or late model? :)
 
So, Oleg, which ones are you going to send to me, early model or late model? :)
You will receive the drivers from late release sample with mark 10GDSH-1-4!.. I have to say that Hari slightly mistaken about his drivers 10GDSH-1-4 - it is also late model, not 10GD-36K!.. So to put everything in its place I will give some information how could you visually distinguish such models if you do not have any mark on the body! First of all you should look on the form and material of the frame, form of high frequency cap and shape of circumferential rubber!..
Also in this article does not mention another one speaker - 10GD-36E (the old name 10GDSH-2-4) which was also made in the Soviet Union as full range driver on stamped metal frame with the same HF cap like 10GD-36K, with slightly different form of rubber rim, but I have to say that the quality of sound of such speaker 10GD-36E is the worst of the 8 inch full range speakers avaible here, so such driver I do not recommend you to buy in near future not even for a big summ of money...)
Look attach photo please...
 

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Mr. Oleg,
What is the material of the voice coil former?
Aluminium? Or Paper?
In my 'limited' experience with vintage drivers Aluminium VC former gives more 'shrill' to upper frequencies then the paper former.
Regards.
 
What were these drivers originally made for?
Tuff, to be honest I did not understand your question.

These drivers were originally installed in a sealed enclosre box of around 30 L to 35L volume with moderate to high stuffing. I have done this simulation in LA and it gives excellent simulated response, better than the OB. If I have an opportunity I would like to build that one too.

After i listened to the FR OB, i thought of adding a subwoofer to supplement the bottom octave below 40Hz and added a H-frame subwoofer using a Dayton 10" classic woofer and it turned out quite well. Now the integration between the woofer OB and FR OB is perfect and as per my taste and liking. Also i was exploring the idea of adding a horn-tweeter in the vertical plane to make this setup completely omni-directional as much as possible. I later did that and also added a small dome just above the horn to allow an early dispersion / diffusion of the HF above 10KHz. All this additional tweaks increased the sound stage, imaging and contributed to an holographic sound stage more like an auditorium kind of listening.

Attached are some images of the outcome.



 
I also did some measurements as it was required how objectively they measure compared to my solo FR OB. Though they sound sonically better than before, but if you notice the SPL response you see that they are no longer ruler flat at the bottom and top end. I am unable to explain why this so, but i can confidently say that they for sure sound better than the ruler flat response. As usual i have included the required plots. These measurements were taken with both the speakers fed and the mic at the sweet listening spot.






Thanks for looking.
 
<snip>I am unable to explain why this so,<snip>
You added a sub which didn't exist before.
You added a tweeter which didn't exist before.
You're measuring with mic at listening position (I'm assuming that this is the sweet spot that you mention). Your measurements contain the effects of your room.
 
I had a small issue in my subwoofer all these days as it was vibrating at moderate volume which was driving me nuts since past 3 days. Finally fixed it today by further tightening the hexnut to prevent any vibration of the driver getting coupled with the baffle. By doing this I think there is atleast 3 dB further boost in the bottom end. Am planning a 1w/1meter measurements today late evening

i did 1w/1m measurement yesterday and below are the SPL and group delay plots,


The high & low Q points in the FR curve is typical of any full range driver and should not be corrected. This is what gives the full range driver its dynamics and high energy levels.


In the FR there is a nasty peak at around 74Hz which is a room mode for 15 feet. Nothing much can be done about this other than room treatment on the wall (window) behind my head in the sitting position. But this is impractical due to WAF considerations. Surprisingly looking at the group delay plot there is no peak in the minimum phase curve at this frequency. That means it can be Equed. Unfortunately my subwoofer amplifier dont have any phase control to fiddle with so cant adjust phase of the sub vis-a-vis to fronts.

What i will be planning is physically turn the subwoofer angle may be 30 deg, 45 deg, 60 deg and 90 deg and check if the subwoofer phase and front phase interact with my room mode and cancel with each other thereby reducing the peak.

FM Spirovious, thecoolestone and Darshan Joshi planning to visit today evening to give a listen to this setup. Also plan to check sabbu DAC and DCB1 with my setup and some branded cables testing.

I have my own DIY cable hooked up which has pretty low capacitance of 22pF for 1+ meter and will be tough to beat because of its geometry imo.
 
Today I a got chance to experience Hari's new system. Last time when I(we) visited him, it was a decent system with tube amp. Now with upgraded tubes.added DIY preamp, OB speakers, DIY sub and a solid source(Marantz UD7007),it was certainly interesting to explore.

We started with vinyl setup connected to his DIY pre and tube amp,but sound was not clean and lacked weight. Adjusting subwoofer level did help, Still vocals were not on warmer side with treble little sharper. We listened for short time and then started with Marantz UD7007 as source.

Hooked up Pen drive and started with some good recorded tracks. Wow,speakers got some warmth and bass started to appear better. Vocals still not good and natural. So Hari did towing in of speakers and yes there was some definite improvement in vocals. Treble edginess reduced. As the time was passing bye, I felt the tube amp becoming warmer in sound signature. At that time we connected Hari's diy dac to check it sound different than UD7007 analog out, but I(we) couldn't. This was interesting. how there was hardly any change? Hari said DAC chips in marantz and DIY DAC are almost similar. So time to change another DIY DAC with different chip.Still not much of the change which is unusual. When I asked about his pre, I found that there is an opamp output stage. Yes that can be it. I have used many opamps with my SSP earlier and some opamps do not change their signature.
So time for different pre. We connected DCB1 and found immediately some looseness in sound. It must be due to zero gain which is not appreciated by the tube amp.
After some time, we changed Hari's much talked telephonic ICs to DAC(Designer audio) one. Difference was immediate with rounded treble. Soundstage marginally improved.Vocals has some thickness now but certain things got softer.
Again discussed with Hari and he explained its low capacitance which improves details.When measured DAC IC capacitance,it was much more than desired and that was making sound warmer. Now to me these figures are not much important as long as sound is improved or near perfect. I have found many times that extra details are heard in music at the cost of natural warmth.
Now hooked B1 and yes it added more warmth to music. By the time I(we) can say that its Hari's pre which do not alter much of the sound.Its can be a good thing as long as one is enjoying music. It sounded very clean though and reason was perhaps better PSU with both current and voltage regulation.
As we spend 2 hrs. tube amp added more and more weight to sound. OB speakers started singing well. Instruments and separation was nice. Subwoofer was adding perfect bass. Vocals still not to my liking, but certainly improved with the time.
Also I have observed, after 6 pm, AC power also improves in our are and all noise reduces by at least 15-20%.

Hearing the Sub performance, we played some movie clips down-mixed by UD7007. With some well recorded clips, sub was punching bass very well and fronts adding perfect details to it. Even with these 2.1 speakers,we were getting the feeling of powerful theater.
Not talking of any surround effect, but tube amp's ability to handle OB speakers was great with good dynamics. We also played YouTube from VUTV to DAC and system didn't let us down. Some orchestra tracks were presented as live performance which is a big plus.
Did quick comparison with Pioneer BD150 with UD7007 and yes marantzs was sounding taut with dark background. Pioneer had good vocals(coaxial out to DAC),but again was sounding loose. After all marantz is 5 times costlier.

Finally it was nice 4 hrs spend with Hari's all DIY system(except UD7007) . Its is always nice to discuss all technical things in person than to just reading in the forum. OB speakers has very good soundstage but need better vocals.The Star performer is DIY SW. It was good in music and movies.Tight and flat bass response. Hari has taken good efforts making his pre and anaog ICs.
Yes sound is a never ending story but this time its one step ahead to his last speaker system.
Cheers.
 
Today I a got chance to experience Hari's new system. Last time when I(we) visited him, it was a decent system with tube amp. Now with upgraded tubes.added DIY preamp, OB speakers, DIY sub and a solid source(Marantz UD7007),it was certainly interesting to explore.

We started with vinyl setup connected to his DIY pre and tube amp,but sound was not clean and lacked weight. Adjusting subwoofer level did help, Still vocals were not on warmer side with treble little sharper. We listened for short time and then started with Marantz UD7007 as source.

Hooked up Pen drive and started with some good recorded tracks. Wow,speakers got some warmth and bass started to appear better. Vocals still not good and natural. So Hari did towing in of speakers and yes there was some definite improvement in vocals. Treble edginess reduced. As the time was passing bye, I felt the tube amp becoming warmer in sound signature. At that time we connected Hari's diy dac to check it sound different than UD7007 analog out, but I(we) couldn't. This was interesting. how there was hardly any change? Hari said DAC chips in marantz and DIY DAC are almost similar. So time to change another DIY DAC with different chip.Still not much of the change which is unusual. When I asked about his pre, I found that there is an opamp output stage. Yes that can be it. I have used many opamps with my SSP earlier and some opamps do not change their signature.
So time for different pre. We connected DCB1 and found immediately some looseness in sound. It must be due to zero gain which is not appreciated by the tube amp.
After some time, we changed Hari's much talked telephonic ICs to DAC(Designer audio) one. Difference was immediate with rounded treble. Soundstage marginally improved.Vocals has some thickness now but certain things got softer.
Again discussed with Hari and he explained its low capacitance which improves details.When measured DAC IC capacitance,it was much more than desired and that was making sound warmer. Now to me these figures are not much important as long as sound is improved or near perfect. I have found many times that extra details are heard in music at the cost of natural warmth.
Now hooked B1 and yes it added more warmth to music. By the time I(we) can say that its Hari's pre which do not alter much of the sound.Its can be a good thing as long as one is enjoying music. It sounded very clean though and reason was perhaps better PSU with both current and voltage regulation.
As we spend 2 hrs. tube amp added more and more weight to sound. OB speakers started singing well. Instruments and separation was nice. Subwoofer was adding perfect bass. Vocals still not to my liking, but certainly improved with the time.
Also I have observed, after 6 pm, AC power also improves in our are and all noise reduces by at least 15-20%.

Hearing the Sub performance, we played some movie clips down-mixed by UD7007. With some well recorded clips, sub was punching bass very well and fronts adding perfect details to it. Even with these 2.1 speakers,we were getting the feeling of powerful theater.
Not talking of any surround effect, but tube amp's ability to handle OB speakers was great with good dynamics. We also played YouTube from VUTV to DAC and system didn't let us down. Some orchestra tracks were presented as live performance which is a big plus.
Did quick comparison with Pioneer BD150 with UD7007 and yes marantzs was sounding taut with dark background. Pioneer had good vocals(coaxial out to DAC),but again was sounding loose. After all marantz is 5 times costlier.

Finally it was nice 4 hrs spend with Hari's all DIY system(except UD7007) . Its is always nice to discuss all technical things in person than to just reading in the forum. OB speakers has very good soundstage but need better vocals.The Star performer is DIY SW. It was good in music and movies.Tight and flat bass response. Hari has taken good efforts making his pre and anaog ICs.
Yes sound is a never ending story but this time its one step ahead to his last speaker system.
Cheers.
Thanks Spirovious for taking time to pen down your listening impressions. Appreciated.

Further to enhance the pre-amplifier circuit i will be adding couple of low-pass filter circuits in the line inputs and phono pre-amplifier stage. Currently the line input when floating gives a buzz due to pick up of stray noise which gets amplified. Same with phono line stage. Also planning to add a LPF at the phono output stage to remove any resuidal noise that can get through. This i believe also will open the mids quite a bit as the HF noise harshness will be reduced to quite an extend. The planned cutover frequency for the LPF is around 100KHz to 150KHz. I had measured the resuidal noise before and it is around 0.5mV which is quite high. In comparison my sony amplifier has a resuidal noise of only 35uV (0.035mV).
 
Hari, work on the positioning of your speakers first. I think it’s a room problem

What cables are you using now?

First get the system to sound right without the sub. Introduce the sub later once you have got your balance right
 
Hari, work on the positioning of your speakers first. I think it’s a room problem

What cables are you using now?

First get the system to sound right without the sub. Introduce the sub later once you have got your balance right
Thanks Prem for your inputs. Unfortunately the speaker positioning will be a constraint for my room for want of space. I have currently gone for the golden ratio room placement with 1:1.6 ratio front to back which gives decent image depth. The speakers are around 22" away from the side walls (center). Room reflections from the sidewall is an issue as the FR driver has a increasing directivity from 200Hz onwards and need to be towed in to avoid the side reflections.

Currently the cables are diy which are polycab telephone cables with copper purity of 99.7% (as per their brochure) which measures 22pF capacitance in my LCR meter for 1+ meter wire. These cables were more detailed and punchy compared to the DAC cables from Darshan Joshi. The DAC cable measured 350pF capacitance and hence highs were getting rolled-off which could sound more releaxed for long time listening.

I think its more to balance the setup vis-a-vis the pre-amp stage, power amp, speakers and the cables so that they could sing in unison.

I am working on the LPF stage for the preamp as i can hear some residual noise at moderate level which can be from stray RF and EMI interference getting modulated with my audio signal. So thinking of adding a simple RC filter to check if they benefit. Also i have studied schematics of Sony Amplifier and Marantz Reference amplifier PM-15S1 which has similar RC implementation in their line inputs and phono output stage for maybe similar reasons.

For the LPF i will be using the following -3dB cutoff frequency to experiment,

Line inputs - CD, Tape and DAC -1 MHz

Phono preamp input - 590KHz

Phono preamp output - 160KHz.

Will implement this over the weekend and post outcome.
 
Today I implemented the LPF in the line inputs with -3dB @ 1MHz. The preamp now sounds superb and now is a completely different beast. The sparkle in the HF is now gone and the overall sound stage is very mellow. In fact I had to remove the 47 ohm series resistor from the piezoelectric horn tweeter to get proper air in the sound stage. Now vocals are quite open and with less sparkle than before.

Never knew that my IC attract so much RF & EMI noise from air. With this LPF implementation o am now able to enjoy low capacitance cable to the fullest. In fact standard interconnects may sound not so good with higher HF roll-off.
 
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Never knew that my IC attract so much RF & EMI noise from air. With this LPF implementation o am now able to enjoy low capacitance cable to the fullest. In fact standard interconnects may sound not so good with higher HF roll-off.
It must be due to vert less shielding on telephonic ic wires.Ics must be working like antenna.
 
It must be due to vert less shielding on telephonic ic wires.Ics must be working like antenna.
IME shielded wires have higher capacitance over 150 pF due to close proximity of the hot and cold points. This itself will rolloff highs earlier.
 
Last month I replaced my telephone cables speaker cables with silver plated copper wire. This wire has a golden ratio cross-section geometry with 1:1.6 mm with the thicker wire for the return line.

With the silver plating on the copper, the highs are very liquid and dark probably due to skin effect playing role here. The overall sound stage moved to open, neutral and less compressed with Vocals getting better presence and intimacy. I am not sure if all setups will benefit with the darker presentation but they are benefiting mine for sure .
 
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