Cornet Finished Yesterday - Power Up and Testing Questions.

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Grover

I'll post some photos later this week.  I finished the project yesterday and I'm pretty proud of my work, even if I do say so myself! :D

I still consider myself a newbie at this, so I thought I'd run by my planned startup and testing routine to see if anyone had any criticisms or any other suggestions.

Power up without tubes and no input our output connections.  If it smokes or the tranny gets really hot, turn it off.

Leave on for about 60 seconds.  With one lead of the multimeter connected to ground and one hand behind my back, test the DC voltages on all the tubes with the other lead of the multimeter.  Record these readings.

Then I will test for both DC and AC voltage at the output jacks by touching the black lead to the outside of the jacks and insert the read lead inside the jacks.

If all still looks OK, then turn off the unit, insert the tubes, connect it up to my system and play.

Ideas, criticisms?  If anyone has voltage readings of their 120v Cornet that they could share, that would be great.

mgalusha

Cornet Finished Yesterday - Power Up and Testing Questions.
« Reply #1 on: 20 Apr 2004, 04:03 am »
You will need to insert the rectifer tube to see any high voltage on the 9 pin tubes. You can check the DC heater voltage with it removed however. Otherwise this sounds fine. I was a little braver, I just popped in all the tubes and flipped the switch. :D Of course I checked everything about three or four times before doing so.

mike g

hagtech

Cornet Finished Yesterday - Power Up and Testing Questions.
« Reply #2 on: 20 Apr 2004, 05:33 am »
Me, I just go for it.  If it's gonna smoke, then it's gonna smoke.  I always do first turn-on with cheap tubes.  And wear glasses.

jh :)

library

Triple checks are not so enough! Sleep!
« Reply #3 on: 21 Apr 2004, 04:25 pm »
Yesterday, I assembled another octal cornet directly from the schematic with lugs. I checked every wiring three times and when I push the power switch with 5Y3 only, nothing happened. There was no heat with 5Y3. The power switch itself is a pilot lamp, and it went off after 2 second. Fuse went out. I tried once more, and the same problem continues. I blewed two fuses. The problem is : I switched wirings between 5V section and 550V section of 5Y3. I took a sleep and check the voltage in the morning. It took 2 mins. After 2 mins of switching wires from the transformer and chassis closing, new Octal Cornet start singing. New one is for my friend. It is strange lugged version shows less hum, higher S/N. It does have goodall and ERO capacitors for coupling caps.

Never make something without sleep. :!:

Grover

Cornet Finished Yesterday - Power Up and Testing Questions.
« Reply #4 on: 23 Apr 2004, 03:47 pm »
I took Jim's advice above.  I stuck in as many Chinese tubes as I could find, ran an extension cord out to the driveway, plugged it in, turned it on and jumped behind the nearest bush.

Everything seemed to work fine - all tubes lit, no smoke.  I'll give her a test drive in the real system this weekend.

mgalusha

Cornet Finished Yesterday - Power Up and Testing Questions.
« Reply #5 on: 23 Apr 2004, 04:05 pm »
Quote from: Grover
I took Jim's advice above.  I stuck in as many Chinese tubes as I could find, ran an extension cord out to the driveway, plugged it in, turned it on and jumped behind the nearest bush.


 :rotflmao:  :rotflmao:  :rotflmao:

Glad it powered up OK, that is a pretty serious power up test. Hope it works great in your system.

mike g

Grover

Cornet Finished Yesterday - Power Up and Testing Questions.
« Reply #6 on: 26 Apr 2004, 03:46 pm »
Listening to the Cornet

I had fun cleaning up my Michell Gyrodeck that has essentially gone unused except for about 3 sessions in the past 10 years.  With only about 5 hours on the Cornet, this is really too soon to give the Cornet its proper due.  So consider these initial impressions.

As others have stated, the Cornet is silent with no hum or buzz present.  The first few hours were one of patience, waiting for the music to start to meld together.  Prior to that there was not really any integration to the highs, mids and bass, as though the players weren't quite on the same page.

What I did notice immediately was a greater sense of space, 3-D soundstage and much better highs than I'm used to.  On the second day of listening, the system started to sound more coherent.  Still the great soundstage, and by now the lows and mids were starting to flesh out better.

By last night, I put one of my favorite Albums one that no one has probably ever heard of.  It's the first solo album by Russell Smith, who was the front man for the eclectic country rock group "The Amazing Rhythm Aces".  Russell has a fantastic voice and I heard things on that album I've not heard in the same way before.  There was a delicacy and air that I've never noticed in the dozens of times I've played the album.  And this is on a mid-priced Grado cartridge that is now 14 years old.  

To put things in perspective, my other preamp is a Music Reference RM5 Mk II with RCA 6922 tubes from Holland.  This preamp was designed for vinyl playback and had a very good reputation in it's day.  My current system is the Basie DIY preamp which the Cornet is connected to.  Even after only 5 hours, the Cornet is an all around better performer.

I'll do a better review later and add some of my experiences with tube rolling.   I may go through a cartridge change prior to that however.