[WireNut]

Many years ago I bought a Forte4 Class A amp and was comparing it to my Adcom 555 and Mccormack 0.5 amps I had at the time.
It was the first experience I ever had with class A amps. At the time I thought the Forte4 Class A sounded dull on the top end and I sold it.
Could it be possible that I thought it sounded Dull because I was use to the brighter sounding Adcom and McCormack?

The reason I'm asking is because I had a 6 month job layoff and had to sell all of the equipment. Now I am back to work and just purchased
a Threshold T50 class A amp that is said to be mint and I'm starting all over again.

The Threshold T50 is only 50 watts Class A but it is only going to be driving the top section of by by-amped system. The top section are MTM speakers at 91db.

Do you all think I've been okay my purchasing the Threshold T50 or will I find it dull on the top end.
The bottom end of my speakers are driven by a 375 watt hafler 9505 which has tons of bass balls.

I have no experience with Threshold and very little with class A amps.

The Threshold will be driving these MTM's only. They are 91 db.



Any advice would be greatly appreciated.

[steve f]

Perhaps there was some type of amp and speaker interface problem. Who knows? Usually things like that happen with highly capacitive loads with things like electrostatics or some fancy woven cables. Amplifier class shouldn't matter except in very rare circumstances. Why don't you borrow a different amp or invite a few people over to bring amps and check things out. Post results please.

Steve

[Ric Schultz]

How an amp sounds (including bright/dull) has very little to do with whether it is class A or AB.  However, almost any amp will sound better with more bias (more into class A)....but what you get is more warmth, palpability, lower distortion and more true musical information.....nothing about dull or bright.  There are tons of things that change the sound of an amp.  Please tell us what it sounds like when you hook it up.  Have fun.....I bet you will like it.

[Folsom]

While I can't confer with anything else written yet, wholly, it is certain that class A isn't dull inherently. The input capacitor of any of them can determine how dull the top end is, no matter how good the amplifier is or is not.

In fact I think it's one of the major flaws among many bigger consumer brands. They can't spend the $ for the extremely expensive caps, so they use some decent ones. The problem is they need bypassed by a small cap or they just don't have the sparkle we all know is in music, undeniably. Obviously bypassing with a smaller cap won't work if the cap is too expensive, or poor quality and harsh.

It's better not to have that top end if you can't stand to hear it, but it's also a whole other level of quality that can be attained. Power conditioning helps keep it from being fatiguing.

[RDavidson]

Folsom, I think you're right, except for cases where amps are DC coupled designs...and have no caps at the input or output.

[Folsom]

Folsom, I think you're right, except for cases where amps are DC coupled designs...and have no caps at the input or output.

I haven't seen one that I specifically recall. I'd think because in order to DC couple you typically need to be able to match the DC level, within reason.

[gregfisk]

I've never noticed a difference of dull or bright because of class, what I have noticed is that a class A amp will sound cleaner and better on the top end and is easier to listen to. When I have listened to different amps in my system and the new one has more top end and sparkle my first impression is usually it's to bright. Then I get used to it and when I switch back to the previous amp I feel like something is missing. I think this is what a lot of people call break in, but the break in is the person not the gear, just my opinion of course.

[RDavidson]

I haven't seen one that I specifically recall. I'd think because in order to DC couple you typically need to be able to match the DC level, within reason.

I'm no expert, but I believe several of Nelson Pass's amps (perhaps not including Threshold and his older creations) are DC coupled from input to output. The First Watt F4 is direct coupled from input to output, but I know this is not a "traditional" amplifier, even in the First Watt range. But yeah, I think you're right. Fully DC coupled amps are not the norm.

[WireNut]

Thanks everyone for your advice. I'm very excited to get the Threshold T50 next week. I've always liked the looks of Threshold. I just found out they are still in business.
I hoping for the best. It a 20 year old amp that was repaired and said to be in mint condition. I hope so. It's exciting putting a new system together after all these years.
I'll let you know how it sounds.

The next thing I'll need is a tube preamp with dual sets of balanced outputs that won't break the bank.

Also I have to get my Hafler 9505 repaired then I'll be really to hook up the whole bi-amp system.

I'm happy to be back.

My thoughts are, I think a good 50 watt amp would be better then a bad 200 watt amp. Watts don't mean everything like a friend of mind thinks. I guess that's why papa nelson stated a company call First Watt.

The Threshold T50 will be the lowest wattage amp I have ever owned.

[Folsom]

A 15w amp wouldn't be a problem if it sounded right, if your room isn't really big.

[poseidonsvoice]

I'm happy to be back.

What? Where the hell did you go? Do you realize you never really LEFT audio? Even if you sell all your gear, and move, it's always in the back of your mind 

Best,
Anand.

[Rocket_Ronny]

When I compared a Threshold Stasis to my Classe DR2 I found the DR2 to be more laid back, perhaps darker, while the Stasis was a bit more lively and forward, a little brighter and not quite as dimensional. So my take on the Threshold stuff was anything but dull. Looks like you picked up a nice amp.

Rocket_Ronny

[WireNut]

What? Where the hell did you go? Do you realize you never really LEFT audio? Even if you sell all your gear, and move, it's always in the back of your mind 

Best,
Anand.

 Yeap your right about that. I could never leave. I knew I'd be building a new system again. Never could get it out of my head. Building it all over again is fun too. I love it.

[WireNut]

When I compared a Threshold Stasis to my Classe DR2 I found the DR2 to be more laid back, perhaps darker, while the Stasis was a bit more lively and forward, a little brighter and not quite as dimensional. So my take on the Threshold stuff was anything but dull.
Looks like you picked up a nice amp.

Rocket_Ronny

Thanks Ronny. I hoping so. I always loved the looks of Threshold. Back in my early years they where to much money for me. Can't wait to get it.

[G Georgopoulos]

I always loved the looks of Threshold.

 

[Tomy2Tone]

 

My, what big caps you have... 

[G Georgopoulos]

My, what big caps you have... 

it's stereo amp,caps are for both channels,i bet this amp is over 100W,the more power the bigger the caps..

[steve f]

Those old Thresholds are great amps. Some of the best amps today follow Pass' general topography. One thing I find amusing is the aluminum plate stock coupling the power supply caps. To this day that's the material used. I'm surprised that special copper, silver or unobtanium haven't found their way into amps. People buy fancy power cords, and 'inferior' aluminum ends up in the power supply anyway.

[RDavidson]

Question : What would better metal do at that spot? Certainly, it doesn't electrically couple the caps. That'd be dangerous.

[steve f]

The caps are coupled that way. My comment about different metals was facetious.

steve

Edit: mr Pass had a static display of one of his amps cover off at the California Audio Show. These days the Aluminum is fancy CNC cut. Beautiful stuff.