Russian K75-10 cap quick review

Anyway, if you’re into having contests to see if friends can identify which model reverb processor is being used on a given recording based on decay texture, then looking up the correct answer in back issues of Tape Op (Eventide SP2016!) these are the caps for you.

Baaronj

Did the GE MPP motor-runs not allow you to focus on ambience depth and/or the trails of artificial reverb ( such as you've indicated you now can using the K75's ) ?

BTW, it was the above quoted paragraph that piqued my interest in the first place and prompted me to post here.

FYI, I end up having similar (reverb ) episodes with my system ( the ability to look into the mix and choose the reverb type when it's been added >>> or even better listening to the "actual room depth" from a good live recording that's used only a few mics ).

In my system the K75-24's represent only 10% of the total capacitance found within my 2 horn circuits.

The other 90% are a boring mix of Motorola MPP type motor-runs, some DC-biased MPP Solens, some surplus RelCaps and then lots of no-name small value bypass caps ( surplus FilmFoil PP and Polystyrenes ) .

My motor-runs account for about 66% of total capacitance . The dc-biased Solens come in at 20%.

I do a lot of capacitor mixing/cascading to get what I'm after.


:)
 
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Audionut

Next Round Is On Me
Having picked up some of these caps from @JP for a song (thanks again), I’m looking forward to implementing them in my iconic project. Not sure how they will stack up against the already purchased Mundorfs.
Maybe in my HK A300 if I have the values?
 
I also am interested in the Emilar/ 288 variant combo. Looking for one more 291B to complete the driver/horn compliment. Thanks for the adapter recommendation. Please indulge me one question... are you bringing in a tweeter on the top?

Back to the original post... The Russians got bumped out of the line up a long time ago. Maybe I need to revisit due to this thread and changes in the xover since. Out of the Oil Cans, I liked the GE's the best , that is until I put in a pair of Mundorf MCap Supreme Alum 600VDC caps.... which seem to do more things right. Driver/ horn compliment is Radian 475 1" on an Altec 32B horn and 15" Jensen P15LL woofers.
 

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@doglv

( You're welcome! for the adapter info. )

I do use a single Fostex 945 tweeter rolled in with a 1.2uF cap ( with a series LCR notch strapped across the terminals > doubling it's rate of rolloff from that of a single cap ).

The network uses 4 components.

Fostex 945N HiPass_1P+LCR_.png

This comes in around 12K as one can see in my pic ( the XSim prediction uses actual response & impedance measurements .
- Green is raw tweeter.
- The grey line is without the LCR notch.
- Red is the filtered response. 12K down to 6K is a 15db drop > so the rolloff rate is 15db per octave.
- FWIW, the upper end of this tweeter/network combo has a 3db down point at 18K.

I don't lowpass the 288-8K ( since it already takes a dive at 13K ).

Since I only hear up about 13K ( last checked some time back ) this gives me a sense of "air" without infringing on or spoiling the nice imaging that the EH500 can conjure up.

If I ever decide to connect up 2 tweeters I'll likely aim them either at the side-walls or maybe even behind the speakers.

:)
 
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I have actually - in a few vintage restorations. I’ve used them in a few spots in my Scott 299b and Mcintosh mx-110z.

They sound more similar to a good quality PIO than to say, a Mundorf Supreme or others higher up the Mundorf line. They don’t have that kind of Mundorf slippery modern sheen. Nor do they have any of the toppiness I associate with a lot of hifi film caps.

They are a more colorful than vintage sounding PIOs. Not more colored nessicarily, just more fun to listen to. Wetter. More pop and drama. More lively. But not by virtue of top end emphasis - more by virtue of an unusually juicy and finely textured midband. I guess I’ve never really heard anything quite like them.

A critic would probably say they’re midrange heavy, but like, so is music. I don’t find them lacking on the top end at all and I really dig what they do for the LF.

The big (ha) issue using them as coupling caps is that their size can be prohibitive.
I put a pair in an Inspire LP27A preamp yesterday they are settling in but will be staying.

Another opinion. Capacitor Musings Part 3 Article By Jon L DIY Audio Kits Reviews
 

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billfort

Administrator
Staff member
Interesting Florida and thanks for the link, hadn't seen that review before.

I'm using the K75-10s in the first PS filter stage of my SET amp and still use them in my DAC where they are a good fit to my ear; a nice combination of film attributes with a little of the technicolor and smoothness of PIOs - great for digits.

 
Interesting Florida and thanks for the link, hadn't seen that review before.

I'm using the K75-10s in the first PS filter stage of my SET amp and still use them in my DAC where they are a good fit to my ear; a nice combination of film attributes with a little of the technicolor and smoothness of PIOs - great for digits.
I concur with your summary of them. If you like the K75's *I* believe you would like the Japanese Amtrans PIO's. Amtrans AMCY Series Film Capacitors There's something 'special' about them too. I needed 1.5uf and found some 5% K75's on the auction site. 4 for $20 shipped. Too bad they don't come in small values. I soldered them in yesterday and they are beginning to open up. I read that they need 100 hours to settle in.
 

billfort

Administrator
Staff member
The Amtrans do look interesting - 0.22uF 630Vdc that I'd use for coupling in my 45/2A3 are $35ea. - I might try them. I settled on Jensen PIOs years ago in that position but trying something new should be fun.
 
The Amtrans do look interesting - 0.22uF 630Vdc that I'd use for coupling in my 45/2A3 are $35ea. - I might try them. I settled on Jensen PIOs years ago in that position but trying something new should be fun.
Bill, attached is some info on the Arizona caps. It appears that they were commissioned by some Japanese audio gurus. They are the new Vitamin Q's. I've used the Blue and Red. Very nice.
 

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I've been poking around for a grab bag of different capacitors to experiment with making some simple crossovers, saw this thread and decided to give these a shot. Thanks for the reviews everyone! I rolled the dice on the slightly dubious tube-store site linked earlier in the thread, expensive international shipping but still overall pretty cheap since most were $1-3 apiece. They provide two PayPal payment options - if you click the first one PayPal tells you it can't process the payment because the government doesn't allow it. If you click the second (presumably linked to a different company) the PayPal order goes through. Never experienced that one before... will let you know when and if they arrive!
 
Just a follow-up, the K75-10 capacitor assortment I ordered from the slightly dubious tube-store website arrived today! So that's about a week from ordering to delivery all the way from Russia... not bad! I wasn't even sure if they'd come to be honest. As others have stated, these things are huge, photos on the internet don't really do it justice... it will probably be a while before I play around with these and have them hooked up to some speakers but thought I'd post here in case others were on the fence about sourcing direct from Russia. IMG_20210331_170815.jpg
 
I've been poking around for a grab bag of different capacitors to experiment with making some simple crossovers, saw this thread and decided to give these a shot. Thanks for the reviews everyone! I rolled the dice on the slightly dubious tube-store site linked earlier in the thread, expensive international shipping but still overall pretty cheap since most were $1-3 apiece. They provide two PayPal payment options - if you click the first one PayPal tells you it can't process the payment because the government doesn't allow it. If you click the second (presumably linked to a different company) the PayPal order goes through. Never experienced that one before... will let you know when and if they arrive!

Be warned that they took a long time to settle in but I really like them. YMMV. The tube-store has been around a while and they are solid. The Pay Pal issue may be due to Russian law.
 
Be warned that they took a long time to settle in but I really like them. YMMV. The tube-store has been around a while and they are solid. The Pay Pal issue may be due to Russian law.
Once my order arrived in less time than it sometimes takes orders within the US my opinion of their legitimacy was definitely altered 😁 would order again!
 
Baaronj

Did the GE MPP motor-runs not allow you to focus on ambience depth and/or the trails of artificial reverb ( such as you've indicated you now can using the K75's ) ?

BTW, it was the above quoted paragraph that piqued my interest in the first place and prompted me to post here.

FYI, I end up having similar (reverb ) episodes with my system ( the ability to look into the mix and choose the reverb type when it's been added >>> or even better listening to the "actual room depth" from a good live recording that's used only a few mics ).

In my system the K75-24's represent only 10% of the total capacitance found within my 2 horn circuits.

The other 90% are a boring mix of Motorola MPP type motor-runs, some DC-biased MPP Solens, some surplus RelCaps and then lots of no-name small value bypass caps ( surplus FilmFoil PP and Polystyrenes ) .

My motor-runs account for about 66% of total capacitance . The dc-biased Solens come in at 20%.

I do a lot of capacitor mixing/cascading to get what I'm after.


:)
Been a while... I'll no m more fully reply to this excellent post when I'm a bit more coherent, but the short answer is the GEs didn't prevent me from cueing in on that spatial information at all. It's maybe just that they do it differently than the Russians and your post reminds me it's probably time to swap the motor run caps back in, and also something boutiquey as well. More to come!
 
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