[JimL11]

Would someone please please help!? I want to make the internal TVR1, TVR2, TVR3 and TVR4 pot settings adjustments after changing the 4 tubes in my SRM-007tII without blowing anything up. I am not an engineer but I am capable of following step-by-step instructions. I have 1 question. Is KG’s outline all I need to do? It seems simpler than the JimL11 + ColoradoTom outline. Many thanks in advance!

KG Outline

- Start with control pots set to the middle

Repeat the following a few times over 30 minutes
- Put voltmeter probes between TP1 and TP2 and adjust TVR1 for zero
(if you have to turn tvr1 more than .25 turn in either direction, stop and get new tubes)
-Then put a voltmeter between either TP1 or TP2 and Ground and adjust TVR2 for zero
-Then put a voltmeter between both TP1 and adjust TVR3 to zero
-Then put a voltmeter between both TP2 and adjust TVR4 to zero
end repeat

JimL11 + ColoradoTom outline

1. TVR1 adjusts voltages between + and - outputs for each channel

a. Insert positive probe into slot labeled “L+” and insert negative probe into slot labeled “L-”.

b. Adjust potentiometer labeled “TVR1” for the left channel. The potentiometer is EXTREMELY sensitive and the meter reading will have a tendency to drift around a bit. The goal is to get under 1 volt.

2. TVR2 adjusts the voltages of the outputs to be close to zero volts with respect to ground

a. Leave positive probe in slot labeled “L+”

b. Remove negative probe from slot labeled “L-” and attach to ground at back of amp. The goal is to get under 1 volt.

3. By alternating negative probe between ground at back of amp to slot labeled “L-” recheck and adjust TVR1 and TVR2 respectively

4. TVR3 and TVR4 - they adjust the plate voltages for the two sections of each 6CG7/6FQ7 to be equal to each other. Connect a voltmeter between both TP1 points or both TP2 points and adjust TVR3 and TVR4 so that the voltage between the two is zero.

TP1 and 2 are connected to the output sockets with 100 ohm resistors, so the voltage at those points is < 0.4 volts different from the voltage at the socket. Both procedures do the same thing, ColoradoTom's just has a little more detail.

Has anyone heard any of Mjolnir's new, more affordable KGSSHV Minis? I am seriously tempted. Apparently slightly lower voltage - 360V rather than 400V - would this result in a slightly less dynamic sound, or simply limit absolute headroom for the highest listening levels? My 007 mk1s should have arrived yesterday but my town is cut off in all directions by snow so it's going to be tomorrow or Saturday at the earliest. Then I will compare against L700 (with 006T) which I expect to be the more balanced system, but hoping to glimpse some of what a 007mk1 can do by listening at lower volumes which shouldn't tax the 006T so much.

The difference in headroom between 360V vs 400V supplies is less than 1 dB, which is negligible. Remember that 100VRMS in the headphones is going to be close to 100 dB, which is VERY loud, and a +/-360V PS means you can reach peak levels that are 17 dB higher. Unless you play your headphones at ear-damaging levels, you're never going to get close to the limits of the power supply.

Now you have caught my interest. How much, more or less, would the components for such an amp cost? Is there a BOM and schematic available for such a device? I don't have anywhere near the time to do this, nor do I have the knowledge, but I would fo it down the road.

The original articles on the SRX-Plus were published in AudioXpress magazine in Nov and Dec 2015 (two issues). The power supply described in there is no longer current, and a new one is imminent, however, you can also use a KGBH supply or the KG Golden Reference supply set for+/- 350V. There is more info in the SRX Revisited and SRX Plus build threads which you can find with an internet search.

 

[mulveling]

Has anyone heard any of Mjolnir's new, more affordable KGSSHV Minis? I am seriously tempted. Apparently slightly lower voltage - 360V rather than 400V - would this result in a slightly less dynamic sound, or simply limit absolute headroom for the highest listening levels? My 007 mk1s should have arrived yesterday but my town is cut off in all directions by snow so it's going to be tomorrow or Saturday at the earliest. Then I will compare against L700 (with 006T) which I expect to be the more balanced system, but hoping to glimpse some of what a 007mk1 can do by listening at lower volumes which shouldn't tax the 006T so much.

Haven't heard his newest 360V minis, but the later 400V minis I heard were on the slightly bright side and not a good match for 009 or L700. Your 007 Mk I would be doing great on these amps, though. He claims the sound is not sacrificed by the cut to 360V, and I don't see a reason not to believe him there. The price cut is significant. But also look for full-sized KGSShv units that hit the market at even lower prices.

 

[Rossliew]

Has anyone heard any of Mjolnir's new, more affordable KGSSHV Minis? I am seriously tempted. Apparently slightly lower voltage - 360V rather than 400V - would this result in a slightly less dynamic sound, or simply limit absolute headroom for the highest listening levels? My 007 mk1s should have arrived yesterday but my town is cut off in all directions by snow so it's going to be tomorrow or Saturday at the earliest. Then I will compare against L700 (with 006T) which I expect to be the more balanced system, but hoping to glimpse some of what a 007mk1 can do by listening at lower volumes which shouldn't tax the 006T so much.

Perhaps I can chime in a bit here. I have the new “cheap” kgsshv from Mjolnir. I use it with my 007mk2, srx pros and Libratum. Absolutely more than sufficient power for those cans and definitely overkill for lambdas. And it is not bright at all unless your source is poorly recorded/mastered. Wonderful pairing with a slightly sweet tonality . I don’t even see the need to go to the full powered kgsshv Nor the Carbon. Unless you want a different sound/tonality I suppose.

 

[statfi]

a slightly sweet tonality

Please help me understand "sweet tonality". I know that it is commonly used but I never understood it. So I would like to take this opportunity to learn. Please tell me, e.g., how it audibly affects what instruments, and what it engineering terms causes it.

 

[Rossliew]

Apologies as I’m not good with such descriptions. I would say it sounds right. Treble is extended but never harsh. There is a certain liquidity in the sound, a cohesiveness throughout the frequencies that makes listening a pleasure. It doesn’t sound artificial I guess. Sorry if this is not of any help.

 

[1note]

How's the Terminator with you're system?

I am yet to listen to this headphone system, but in my CD speaker system (Jay's Audio CDT3 Transport, Custom 8w single transistor Class A battery powered mono blocks, Rey Audio K-Mons) it is excellent and easily bests my Rey Audio R-DAC in every regard. And the R-DAC is significantly better than the DAC in my Esoteric K03X. I find the Terminator to be tonally neutral, having wonderful realistic detail, great rhythm and great dynamics. I am enjoying it immensely.

 

[oktapod]

Well, the 007mk1s are here and despite everyone saying that they'd sound poor with the 006T, surprisingly they sound pretty good. Certainly better than I was expecting. For my listening levels, I could (and will) easily live with this combo until I pull the trigger on a better amp. In comparison, the L700s, sound a tad 'hot', with more treble energy. That suits certain tracks, whereas the 007 suits others better. Either could be considered superb headphone sound, though I can't get away from the very strong hunch that I am going to really take to the sound of 007mk1s driven *properly*.

Which brings me to my next question. I thought I might find the tonal balance a tad dull compared to the L700s, but I think Stax got the voicing about right. Will a KGSSHV change the overall tonal balance, or just add refinement and better control? If I could criticise the sound from the 007mk1/006T, I'd say that on certain busier tracks (but not all) there's a slight congestion to the sound and perhaps the bass itself is a touch bloomy. But against my expectations, this is relatively benign.

Very comfy phones too, I can see we're going to get along just fine

 

[Whitigir]

007 mkI is better with a solid state amp than tubes amp

 

[Gnasherrr]

Well, the 007mk1s are here and despite everyone saying that they'd sound poor with the 006T, surprisingly they sound pretty good. Certainly better than I was expecting. For my listening levels, I could (and will) easily live with this combo until I pull the trigger on a better amp. In comparison, the L700s, sound a tad 'hot', with more treble energy. That suits certain tracks, whereas the 007 suits others better. Either could be considered superb headphone sound, though I can't get away from the very strong hunch that I am going to really take to the sound of 007mk1s driven *properly*.

Which brings me to my next question. I thought I might find the tonal balance a tad dull compared to the L700s, but I think Stax got the voicing about right. Will a KGSSHV change the overall tonal balance, or just add refinement and better control? If I could criticise the sound from the 007mk1/006T, I'd say that on certain busier tracks (but not all) there's a slight congestion to the sound and perhaps the bass itself is a touch bloomy. But against my expectations, this is relatively benign.

Very comfy phones too, I can see we're going to get along just fine

Grats on the getting the 007mki. I'm facing the same debate as well. I'm building a carbon now and choosing between $800 l700 and $1600 007mk1. Really no idea what to do.

 

[Whitigir]

Grats on the getting the 007mki. I'm facing the same debate as well. I'm building a carbon now and choosing between $800 l700 and $1600 007mk1. Really no idea what to do.

I would wait on the next Stax flagship or get the VOCE or all of them...lol

 

[Gnasherrr]

I would wait on the next Stax flagship or get the VOCE or all of them...lol

But $800 L700 tho...

 

[Whitigir]

But $800 L700 tho...

I don’t know about l700, but I do know 007 and MkI is a pretty good match

 

[VRacer-111]

But $800 L700 tho...

Or brand new L300 Limited 80th anniversary for $720 if you are considering the L700...

 

[kylev]

What a great answer Jim. Thank you for informing us. I was worried I was being too critical of this amp, but for me, I think I'll be looking to upgrade soon!

My opinions here are my own. I'm new to the hobby. I don't read the reviews and follow the flock, yet. These are my observations and I'm doing this intentionally as of right now.

What's the sense in spending 10k on gear if you can't appreciate its greatness or point out faults in a lesser quality setup.

When I first tried the 009s, I knew they are something special, just not dialed in as say perhaps, my focal utopias with chord hugo 2. That hit me immediately as completely wonderful.

Bhse... kgsshv... bhse... kgss carbon... I guess I'll have to flip a coin tonight

Get Carbon, its really good, all rounder amp! I have heard BHSE last time, but personally I still prefer Carbon for all tracks. Thanks to @soren_brix for the amp, love it!!

 

[Whitigir]

Remember to not inhale too much “carbon”