Show us your Power Amplifiers.

[ghost4man]

1 hour ago, Wimbo said:

That meter reminds me of ................

You know what, looking at that gear you are getting a big piece of sold man meat that looks like it'll control any speaker it has to dance with. 

 

It gives me the sense that it's costly but worthy of the cost as opposed to a lot of gear these days that light literally and figuratively speaking. 

 

What a weapon for an amp. 

[Luc]

8 hours ago, mwhouston said:

Year of manufacture? 

Was made between 1984 to 1992.

 

Very well remembered Mozilla-esque & Gargantua-esque heavyweight powerhouse which needs two people to be lifted : 63 kilos.

Able to output 2x 1,2kW at 1 Ohm, one might imagine this having been aimed at PA reinforcement for deaf audiences but, in fact, the circuit's engineering are very much fine-tuned and almost microscopic.

The secret inside lies in the two secondary transformers : these are "In Phase" transformers which echo the Signal In-Phase Filters of the Integra P-308 high-end preamplifier. In Phase transformers are to cope with the reactive load of loudspeakers, and not only their resistive aspect ; these transformers are to avoid the phase shift between voltage and current in the amp-to-speaker signal path.
Most pronounced around the speaker's resonance frequency, this phase-shift also happens between the voltage and the charging current in the amplifier's power supply ; these charging currents may start fluctuating along the low-frequencies contained in the musical signal. Out-of-phase charging currents can generate electromagnetic flux which in turn often induces voltages of the same incorrect phase in the nearby driver stage (through which the audio signal passes) ; the problem is then, naturally, sent to the loudspeaker... muddy bass and blurry soundstage.
Real Phase transformer are inserted between the positive and negative charging currents of the the power-supply and the capacitors : as the positive and negative currents pass through the transformer's two windings, unwanted peaks and dips cancel each other out - in phase ! You can see the schematic of the Real Phase system by clicking the "more" button below - click !

Otherwise, the Grand Integra M-510 is real dual-mono amplifier : two power cords and two toroidal power transformers ! A fifth and common trafo is used for the meters and out-of-the-signal-path circuitry such as speaker relays. Each channel benefits from two 33,000µF / 100V capacitors - for a 99,000µF total... Each channel's power board holds 7 pairs of (I believe Sanken) transistors, 28 in toto. Gargantua-esque indeed.
Linear Phase Switching is included for true waveform linearity (see the Integra P-308 page on TVK for details) and an elaborate complex protection circuitry kicks in if necessary - 1,2kW per channel can transform your fragile tweeters into live frisbees.

A cool "waiting monitor" flashes some leds geometrically while a dimmer allows to switch off the VU meters' lamps ; gold-plated terminals and solid wood sideburns give the ultimate in reliability and looks, respectively. Both the variable and direct inputs are single-ended, though. The front flap hides the speaker selector (A, B, A+B), variable input pots, dimmer, and meter range selector (x1 or x0,1).
The Onkyo Grand Integra M-510 was lavishly displayed in a "Big New Sound" section in Stereo Sound #73 (winter 1985), and was seen in many a japanese Onkyo ad, often accompanied by the Grand Scepter GS-1 horn loudspeaker. However, this golden Grand Integra now remains... quite invisible.

Looks-wise a bit heavy-handed and tacky and not really discrete with its 27cm in height, but, hey - you can't be Gargantua and look like Minnie the Mouse !

 

Sadly all the links are dead in this article and obviously I didn't write this as I got lost at; "these are "In Phase" transformers which echo the Signal In-Phase Filters "

 

No idea what he's talking about and to be honest I'm only interested in the VU meters and how they will look in my room with black walls and black carpet and a glass of red in my hand.

 

*My mate's one was one of the duds manufactured in the Japanese Year of the Dog when a newly returned engineer from East Germany got caught up in the euphoria of the Berlin wall coming down and they built some really gruddy cheap ones for the mass market, for dummies basically and he being newly awaken to the wide world misinterpreted the Year of The Dog as The Year of the Dud.

 

Postage and a few dollars plus a bottle of 12 year old Metaxa should clinch the deal I think.

 

** Bait tossed out...waiting....

 

 

 

[JukKluk2]

2 minutes ago, Luc said:

No idea what he's talking about and to be honest I'm only interested in the VU meters and how they will look in my room with black walls and black carpet and a glass of red in my hand.

It's actually better if you have a glass of red in each hand. That way you can optically filter the V.U. meters simultaneously through the wine glasses. When both meters are clearly visible it's time to add more Durif.

[Guest thathifiguy]

 I've thought about letting her go, but can never bring myself to do it.

[Luc]

6 minutes ago, thathifiguy said:

 I've thought about letting her go, but can never bring myself to do it.

Imagine having this and a Vincent Black shadow in the garage...bliss!

 

Come round and listen to my Vincent...haha!

[Eggmeister]

51 minutes ago, Luc said:

No idea what he's talking about and to be honest I'm only interested in the VU meters and how they will look in my room with black walls and black carpet and a glass of red in my hand.

 

*My mate's one was one of the duds manufactured in the Japanese Year of the Dog when a newly returned engineer from East Germany got caught up in the euphoria of the Berlin wall coming down and they built some really gruddy cheap ones for the mass market, for dummies basically and he being newly awaken to the wide world misinterpreted the Year of The Dog as The Year of the Dud.

 

Postage and a few dollars plus a bottle of 12 year old Metaxa should clinch the deal I think.

 

** Bait tossed out...waiting....

 

 

 

 

I think you mean a 12 Star Metaxa 

 

Edited November 12, 2019 by Caelian

[mwhouston]

22 minutes ago, Luc said:

Imagine having this and a Vincent Black shadow in the garage...bliss!

 

Come round and listen to my Vincent...haha!

I mate of mine had one, 100% restored and he rode regularly.

[astormsau]

I finally got a Mcintosh preamp to go with my mc275 power. I feel like I’ve played a role in uniting a long lost family [emoji1787]

[Luc]

 @astormsau  Blue VU's

 

3 minutes ago, mwhouston said:

I mate of mine had one, 100% restored and he rode regularly.

I knew a bloke who had/has one. 54 or 53 model if i have that right. What a mammoth thing it is.

[Wimbo]

2 hours ago, Luc said:

Come round and listen to my Vincent...haha!

Do you have a Black Shadow Luc?

Original or Egli?

Edited November 12, 2019 by Wimbo

[Assisi]

My Soulution  501 power amps on the bottom shelf and the Soulution  520 Pre on the shelf above on the right hand side

John

[betty boop]

power amps ? no problem have a few hooked up and ready to go  

 

2ch musical fidelity m8 500S

 

 

 

and obligatory nude shot for those so inclined  

[betty boop]

more channels ? no problem 

 

7 channels of aussie goodness in form of iron fist in velvet elektra glove

 

 

 

ah nude shots , found ... this is actually of model prior I also own but they are still pretty similar underskin  

 

power supply is full height of the case. Massive heatsinks on either side for passive cooling, and overall runs relatively cool as result 

 

 

nice big torroid (weighing 14kg I understand)  and top quality nichicon muse caps 

[mjs]

On 10/11/2019 at 2:58 PM, andyr said:

 

 

Very interesting, Les.

 

Which drives your 1.7s better - the JC1 monoblocs ... or the ME850?

 

I recently heard an ME850 driving some 3.7s - and that was simply wonderful sound.  Could it be that JC1s would be even better??? 

 

Andy

 

Andy,

 

As the owner of the ME850/ME25 and MG3.7i's in question, thanks for the comment. I have to admit I am still on a journey of discovery with the amps. I have had them for 18 years but, had them both serviced (new caps etc) and the 25 upgraded recently. Have been carefully and enjoyably listening to a range of familiar music recently as well as some new stuff (like the 45rpm vinyl we listened to) and continue to be staggered by the inner detail that is present. No complaints from me about the synergy of the ME amps and the Maggies. The soundstage is almost holographic. 

 

cheers, Malcolm 

[Uncle Seth]

On 11/11/2019 at 8:34 AM, DRC said:

Krell Evolution One monoblocks. 1.8 kW into two ohms but silkily smooth and detailed even at low listening levels.

Pretty enough, but:

JC1 lab results. Class A up to 29W (where most listening would occur).
Power at clipping (about 1% THD):
586.5W into 8 ohms
1154W into 4 ohms
2255W into 2 ohms
4200W into 1 ohm

 

https://www.stereophile.com/content/parasound-halo-jc-1-monoblock-power-amplifier-measurements

[andyr]

Yesterday, I finished a project which has been going on for a couple of months - that of changing from this:

 

 

 

 

I built the 'black box' 15 years ago, to house:

• a 3-way active XO
• 3x AKSA monoblocs
• 4x power supplies.

 

To the new setup - which is this:

 

 

 

 

The smaller case houses an AKSA 100w 'Soraya' monobloc - with an upgraded CRCRC power supply.  This drives the bass panel (which is currently just resting against - not bolted to - its braced stand ... and not connected).

 

The larger case contains a NAKSA 80 (stereo) PCB - and an EI power transformer.  This drives the (3 ohm) mid panel and (2 ohm) ribbon.  A 3RU Modushop case was needed, due to the height of this power transformer - which gives a generous heatsink for the output devices. 

 

Here are pics of the fronts and backs of the amplifier cases:

 

1.  Soraya monoblocs

 

 

 

 

2.  NAKSA 80 stereo amp

 

 

 

 

 

I'm keen to hear what the new PSes do to the sound of the bass panel amps - but, unfortunately, the tech who re-wired the panels didn't bother to connect up the new (foil) wire he used, to the solder pads which the previous round-wire had been soldered to (and which my spkr cables are connected to)!    So I have to fix this problem before I can have a listen. 

 

Andy

 

Edited November 16, 2019 by andyr

[mwhouston]

3 hours ago, andyr said:

Yesterday, I finished a project which has been going on for a couple of months - that of changing from this:

 

 

 

 

I built the 'black box' 15 years ago, to house:

• a 3-way active XO
• 3x AKSA monoblocs
• 4x power supplies.

 

To the new setup - which is this:

 

 

 

 

The smaller case houses an AKSA 100w 'Soraya' monobloc - with an upgraded CRCRC power supply.  This drives the bass panel (which is currently just resting against - not bolted to - its braced stand ... and not connected).

 

The larger case contains a NAKSA 80 (stereo) PCB - and an EI power transformer.  This drives the (3 ohm) mid panel and (2 ohm) ribbon.  A 3RU Modushop case was needed, due to the height of this power transformer - which gives a generous heatsink for the output devices. 

 

Here are pics of the fronts and backs of the amplifier cases:

 

1.  Soraya monoblocs

 

 

 

 

2.  NAKSA 80 stereo amp

 

 

 

 

 

I'm keen to hear what the new PSes do to the sound of the bass panel amps - but, unfortunately, the tech who re-wired the panels didn't bother to connect up the new (foil) wire he used, to the solder pads which the previous round-wire had been soldered to (and which my spkr cables are connected to)!    So I have to fix this problem before I can have a listen. 

 

Andy

 

Absolutely extreme. I admire your dedication.

[andyr]

31 minutes ago, mwhouston said:

Absolutely extreme. I admire your dedication.

 

Thank you, Mark! 

 

The amps certainly have a bigger WAF factor than they did before.    And I'm pleased to find that the NAKSA 80s show absolutely zero hum/hiss when I put my ear against either the mid panel or the ribbon.  Mind you, I did go the the extent of:

a.  putting a case divider between the power transformer / IEC inlet / fuse / power switch and the N80 PCB, and

b.  enclosing each pair of traffo secondary wires in an earthed shield (earthed to the case divider).

 

This involved quite a lot of extra hours of work - but the result is as I hoped it would be.    See pic:

 

 

 

 

I've done the same thing with the 'Soraya' monoblocs - so can't wait to be able to hear them.

 

Andy

 

Edited November 16, 2019 by andyr

[mwhouston]

Have you listen to both Hughs amps as a full system and is there a fav? 

[andyr]

7 hours ago, mwhouston said:

Have you listen to both Hughs amps as a full system and is there a fav? 

 

No sorry, I haven't, Mark.  The amps have always been in a fully active system.

 

Andy

 

[ThirdDrawerDown]

Congrats Andy! :)

[Uncle Seth]

@andyr, good work, as well as pretty (to the hi-fi eye).

[TerryO]

These Icon MB90 MK2’s that I recently purchased from another SNA member are stunning amplifiers in every way, they really need to be heard to be appreciated how good they are.

 

cheers Terry

 

 

Edited November 17, 2019 by TerryO

[mwhouston]

12 minutes ago, TerryO said:

These Icon MB90 MK2’s that I recently purchased from another SNA member are stunning amplifiers in every way, they really need to be heard to be appreciated how good they are.

 

cheers Terry

 

 

Do look good with a retro feel. 

[TerryO]

Considering it is a 1994 build this great looking Sansui 907 Limited is one very nice sounding amplifier that easily drives my VA Concert Grands, at a recent gtg it didn’t embarrass it self against a trio of $20k plus amps.

Edited November 17, 2019 by TerryO