[Musicalmaniac]

I flipped on my Cornet a while ago and noticed a very loud buzzing from the transformer that can actually be felt vibrate through the rack it sets on.  I have noticed a slight hum on starup before that went away after it warmed up but this buzz got my attention enough that I just switched it back off right away.  This is the older original Cornet that was extensively modded my the fella I purchased it from with some large Mundorf caps -etc.  Any suggestions?  I've been considering upgrading from this unit for a while anyway but if the tranny needs replaced and any major benefit could be accomplished through this sort of mod, maybe I need to hold off?  Any remomendations would be valued. 

[hagtech]

What is your ac line voltage? 

jh

[Musicalmaniac]

Jim,  My voltmeter shows a very consistant 120.2 volts.

[hagtech]

Ok, then we have to check the output voltages.  The easiest is to chek heaters.  If everything is running high, then there might be a breakdown arc in the primary windings.  I believe this is the common cause for failure.  These trannys (the original 270BX) do not handle a high line voltage well.  The primary inductance starts to collapse, resulting in temperatures to jump.  This eventually leads to an insulation breakdown and short between windings.  Total failure is when the arc jumps and primary draws too much current, blowing a fuse.

My original solution was to switch to the 370BX, which does not have the problem.  In my newer products, I have successfully used the older Hammond style trannys by limiting the primary voltage to 115V.  You wouldn't believe how much difference that little 5V can make.  That, I believe, is the crux of the issue.  I first did this on my CLARION, where I inserted lamps in series with the line to drop voltage.  It worked great.  On the CASTANET I use power resistors.  Not only do they drop the voltage to reliable levels, but they also help to form a nice RC low pass filter, removing RF crap from the line.

jh

[Musicalmaniac]

Ok,  It may be getting over my head with specs and such. I don't have any specs to check the heaters or for that matter know the schematics to do this.  If it was safe to say swapping out the tranny was the correct move, I could do that.  One question is could I gain significant sound quality by upgrading or changing to a different tranny, and if so what part number and make and model would you suggest.  I could also handle running the resistors in line with the tranny if need be.  I would really like to step up the sound quality one way or the other and if I will be limited with this unit maybe I should just move it along and let someone else enjoy what it has to offer and upgrade right away.  Any suggestions there?  I'm not real familiar with what you offer but have heard good things about the Trumpet. Any suggestions appreciated.

[hagtech]

My recommendation is to go buy a TRUMPET.  Better yet, buy two of them (one for your wife)! 

Or, save a few bucks and replace the existing CORNET tranny with a Hammond 370BX.  Available from www.tubesandmore.com and other fine reputable dealers.  Send me an email at jim@hagtech.com and I can send you a small board that helps wire up the multiple primaries.

jh

[BobM]

If you're looking for better sound you should definitely consider the Trumpet. It is easily 2 steps up from the Coronet. You may never need another phono stage upgrade again. I've had both and can speak with some confidence on this. As good as the Coronet is, it can't touch the Trumpet for dynamics and tonal shadings, which is what makes the big boys shine over the rest.

Enjoy,
Bob

[Musicalmaniac]

Thanks for the help and suggestions.  Would the larger Hammond 370 bx offer any significant sonic benefits above the 270 bx ?  If not, are there any other options worth considering for trannies?  I just got around to checking and see the Trumpet is not on the web sight.  Is it available as a cusom order?  Any good used Trumpets out there for sale?  I may just get one for my wife as well if the price is right!  I know they are spendy and it sounds like deservingly so.   Unless I traded this Cornet to someone that wanted it with a trannny that is questionable I think it needs it's problem taken care of anyway.  I've never been dissapointed with it, It has some high dollar cap upgrades and such.  I've heard from some reputable techs that the tranny is the most important overlooked part in any amp and should be where the attention is placed.  I'm not a tech, and hardly understand basic home wiring but  can solder and work with my hands and have a mechanical aptitude.  In other words if I know what wire goes where, I'm not in the least bit intimidated.   So I guess I'm at putting the Cornet back to stock specs and upgrading to a better phonostage, Upgrading the Cornet to make it somewhat better if possible and keeping it for a while longer or trading the Cornet in the way it is for something sigificantly better.    Am I overlooking any worthwhile options? How far is it worth going with the Cornet?

[hagtech]

The TRUMPET will soon be available again - in new skins.  It will be part of the www.haglabs.com lineup, as a "heritage" product.  I use same style chassis as the other machines, but split the TRUMPET into two boxes.  Makes for a quieter installation and fits onto any rack now.  Price expected to be $2499.  No pics yet.

jh

[Musicalmaniac]

I'll be keeping my eyes open on the new Trumpet, in the mean time in your opinion would there be any sigificant sonic benefit from upgrading the transformer on the Cornet from the 270 bx to the 370 bx, and what about even higher quality transformers?

[hagtech]

Sonically, the benefit is that you get rid of the buzz.  It is a more robust design compared to the 270BX.  And it costs more to boot.

jh