MKP1837 SQ: new black case vs old blue case

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I'm going thru my Schiit Yggdrasil DAC and replacing the stock WIMA caps in the output section (The anti-imaging filter).

For 2 values, 220pf and 330pf, I replaced the FKP2 WIMAs with AMTRANS copper foil polypropylene film caps of the same value. After a week run in, I thought it improved the overall clarity of the high frequencies and gave a blacker background.

Another value WIMA cap that I intend to replace is 2 pair of 0.1uF@100V MKP2. PCB space is at a premium with 5mm pitch leads and SMD mounted close. The Vishay MKP1837 makes a perfect fit, and has a very good reputation on the internet. So I ordered from Mouser. The new ones arrived and have a black case, and on further researching, found the case has changed material from the blue case polypropylene w/epoxy seal to the black molded polybutylene terephthalate.

Was wondering if there are any opinions if these new manufacture Vishay MKP1837 have the same SQ as the older blue cases versions written and reviewed?
 
I'm a little bit confused. Do the Amtrans AMCH really have copper foils? Parts Connexxion and HiFi-Collective say nothing about it. No other Amtrans will fit in place of a FKP.
Why do you think a MKP1837 should be better than a MKP2?

P.
 
Last edited:
For info on AMTRANS, look to the source: AMTRANS Products Information AMCH

As for opinions on the Vishay MKP1837, here are several of the many capacitor comparisons on the 'net:

Humble Homemade Hifi - Cap Test

Capacitor Musings Article By Jon L DIY Audio Kits Reviews

Audiophile Musings: The Vishay MKP 1837 Review and Modification

Also, measurements on the Blowtorch thread show distortion and noise of the MKP1837 equivalent to polystyrene film and foil.

I know WIMA MKP2 are lacking the last bit of resolution needed in a highly resolving system. First experienced that years ago by replacing the stock WIMA MKP2 caps in an Altmann Attraction DAC with REL Teflons. IMHO, WIMA MKP2 are a weak link.
 
Last edited:
I bought some of those after reading all that, sounded bright and harsh in decoupling some fairly hi esr electrolytic capacitors in an op amp supply.
Not sure about coupling, could be fine there, since that was the premise of the test I had read.

Maybe some polystyrene in your filter would be good?

I am using the same wima in those applications with no complaints...
 
Thanks for the polystyrene suggestion, Phase. The 0.1uF value is not available in the lower voltages/smaller packages from quality suppliers. The MIT and RELs are 400-630V and are huge. I'll pass on the EBay/Chinese sourced parts.

Today, I've replaced the WIMA MKP2s in my Yggy with the new production black Vishay MKP1837s I bought from Mouser. Tipped the sonic balance towards the HF and a bit edgy/tizzy. Will play them in for several days and hope they settle some. In the mean time, will inquire with Parts Connexion if their supply of MKP1837s are blue case NOS. If they are, will get two pair and swap out the black ones and compare.

Will report back with what I find.
 
1837 @ PcX

Thanks for the polystyrene suggestion, Phase. The 0.1uF value is not available in the lower voltages/smaller packages from quality suppliers. The MIT and RELs are 400-630V and are huge. I'll pass on the EBay/Chinese sourced parts.

Today, I've replaced the WIMA MKP2s in my Yggy with the new production black Vishay MKP1837s I bought from Mouser. Tipped the sonic balance towards the HF and a bit edgy/tizzy. Will play them in for several days and hope they settle some. In the mean time, will inquire with Parts Connexion if their supply of MKP1837s are blue case NOS. If they are, will get two pair and swap out the black ones and compare.

Will report back with what I find.

I recently picked up some 1837s from PcX, they were the black case versions... (.1 uF). Have not used any yet.
 
I had already swapped out AMTRANS polypropylene film and copper foil for the stock WIMA FKP capacitors in the 220pf and 330pf locations. I like 'em. Might try some ERO KP1834 polystyrene film and tin foil caps someday day. NOS are lots cheaper than new REL.

The KP1837 I wrote of are MKP, as I could not find a film and foil in 0.1uf value that fit the 5.08mm lead spacing and the limited PCB real estate.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.