[vconsumer]

Last weekend I finished building a Cornet 2. Since Sunday evening, I've been spinning record after record. Fortunately, I have the week off and a closet full of records.
I didn't build the Cornet 2 stock. Instead, I used a 8x12" chassis and took advantage of the extra space by locating the transformer, rectifier, and power supply caps away from the PCB. The outer edge of the transformer is now about 11 inches from the output tube.
I used (unbypassed) motor run caps for all the power supply caps, Sonicaps on the board, and Northcreek Music Systems' Harmony caps on the outputs. Resistors are 1% MF.
Tubes are a Sino 5AR4 and EH gold pin 12AX7s from Jim McShane. After four days of break-in, in the output tube position I've come to prefer a Brimar 13D5 over an RCA cleartop or RT 12AU7WA. I plan to buy some Sovtek 12AX7LPS from Jim McShane as well as a few rectifiers and more 12AU7s to roll.
I'll post photos after the holiday.
For now, I'm one very impressed customer of Hagerman Tech. Thanks Jim!

[hagtech]

Hmmm, maybe I should have designed in a cutoff switch.   

Regarding the LPS, I find they are sonically the same as the LP, but the spiral winding gives the structure a totally different microphonic.  Instead of a ping or thump, you get more of a shimmer.  Not sure if that is better or not.  Anyway, it is why I chose the LP for production instead of the LPS.

jh

[vconsumer]

Here's a photo of the partially assembled Cornet 2. The transformer is located in the far left corner. The bubble wrap on top of the bank of motor runs isn't part of the amp.

[analog97]

This summer I fixed my outside air conditioner.  I found the problem to be 2 blown (swollen, actually) motor run capacitors.  They look just like the ones used in your photo.  They have the same aluminum casing and those clip-on connectors on top.  What am I missing here?  Can these capacitors provide the sound quality of a "good" cap, eg an Auricap?  I would love to hear your machine!

[vconsumer]

I've been using motor run caps in my gear for a couple of years now. No failures. They sound much better than electrolytics. Designing around them is a pain because of the size, but worth the result.

[Bill Epstein]

I've been using motor runs for awhile 2. The filter/output cap in my crossover is an Aerovox which sits next to an Obbligato oil 'n film; I alternate them and can't choose a winner. Both kill Auricaps (which used to be my faves), Mundorf M's and other film caps I've tried. They're really good in small values too like vconsumer uses in his Cornet. Obblis in my ARC pre-amp and 45 amp as well.

Lots on E-Bay and grainger has GE's in stock. make sure you get motor run, not motor start. Motor runs on E-bay are getting more expensive than Obbligatos!

[hagtech]

Motor run caps are designed to operate at very high ac current.  Huge flux fields. 

jh

[Bill Epstein]

 

[Rocket]

Hi,

Just started using classic cornet that I've had for a very long time.  I was using a denon dl103 cartridge and it had hum that really annoyed me.  The cornet that I bought had stock caps and I thought it sounded okay but it didn't really grab my attention.  I used lundahl 9206 stepups in the cornet.

Recently, a fellow member called Bluesky who is a fan of hagtech products upgraded the caps for me.  He installed obbligatto caps that I think are made in china? that I have never heard of but he said were as good as hovland caps.

Due to an unfortunate accident I destroyed my denon dl103 cartridge and I just had a benz micro mc20e2 high output mc cartridge installed.  I decided on this cartridge because I had bluesky remove the stepups in the cornet.  Anyway, the sound is much improved and actually it doesn't sound like the same phonostage.

I use a nice bluenote de medici phonostage that retails for about $1300us and I think the classic cornet sounds in the same league.  I think the bluenote may have a little deeper bass but in all other areas its pretty hard to pick a difference.

I'm pretty happy with the sound quality I'm getting now.

Regards

Rod

[analog97]

Motor runs on E-bay are getting more expensive than Obbligatos!

OK somebody has to help me understand this.  I bought 2 motor run capacitors to fix my air conditioner (and, no, I was not interested in sonics!!).  The cost was $10.  Should we now forget about Sonicaps, Auricaps, Mundorfs?  What am i missing?  I am from Missouri until Jim sets me straight!

[GRD]

Analog,

Good question.  Lots of people swear by motor runs in the B+ supply vs electrolytics.  Some have posted on using them for coupling caps.  There are a few web pages around where people have compared motor runs with other audio caps.  My take via these posts is the motor runs aren't too bad, but there's always a high end cap that is preferred.  Perhaps someone here has real world experience they can share.

[analog97]

Thanks GRD for the reply.  It just seems peculiar going to a plumbing supply house for an "audio" capacitor.

[bluesky]

Hi Everyone

As Rocket pointed out I am a big fan of the Obbligato film caps.  I recently put some into Rocket's blue Cornet and ran it for a while to make sure everything was working fine before posting it off.

I had the Cornet in the loungeroom running whilst I went back to my workroom to do some more soldering..... A few minutes later I was quite stunned to hear the difference even from a couple of rooms way!  It was mainly the dynamics, ie the difference between loud and soft that first hit me, then upon closer listening I noticed that the soundstage was also way better.

I can't say I have done direct comparisons with heaps of other high end caps but I have read of other people's take on these caps and the consensus is that the Obbligatos are at least the equal of Mundorf silver oils.  I understand they are made by a very large Chinese cap manufacturer and are sold by DIY Hifi Supply at a price that makes us DIY'ers very happy.

I now use them in all my projects unless I find something "on special" like some Jensen PIO's recently for a couple of bucks a piece.

Bluesky   

[Rocket]

Hi Bluesky,

The obbligato caps seem to be a pretty good pickup, although I can't comment on their sound quality compared with other caps.  The pricing was for the caps was pretty cheap (i've spent more on blackgates and v caps) and has made a really good improvement in my system.

Regards

Rod

[vconsumer]

Here are photos of the innards of my nearly complete Cornet 2. Still need to tidy up here and there.

[hagtech]

You might end up with hum and buzz.  Best, I think, to return the grounds for each cap separately to it's specific location.  Can be difficult to remotely locate the caps.  There's a reason they are positioned where they are.

jh

[vconsumer]

Easily enough done. I can hear hum clearly from about a foot away from the speaker, but not from my listening position.