Thread: JOB 225 2-channel Power Amplifier ... update ...

My Job 225 ran burning hot, burning hot. I found one of my rca inputs to be loose and turning/twisting. I presumed this was causing a short, and sent the job for service, which was very expedient. Supposedly not a short..... but upon return it performed flawlessly without becoming burning hot

I guess that your loose rca input had its internal ground lug very loose also, making bad ground contact and this unstability on ground reference level is specially harmful for this DC coupled, wide-bandwith amp. I guess that it may provoke the overheating you noticed. I am glad that Job have fixed quickly the problem .

Originally Posted by Lutfisk

Cool info about a hot amp.
Could powercables also affect the interconnects the same way and freak out the amp ?

I leave some general recommendations from the goldmund/Job people for cabling, electrical issues, etc...

The Goldmund Ultra-fast Electronics Idiosyncrasies
In order to reproduce the transients and the dynamics in music with a lifelike quality, the Goldmund electronics uses extremely wide bandwidth in their circuitry, with literally zero phase error and time error. This is the main difference in the way they are designed.
However, this extreme bandwidth in the circuitry is making the Goldmund electronics more susceptible to be affected by incorrect installation and cabling. When proper care is not applied to the cabling, the grounding and the AC power connection of a Goldmund system, severe RF problems may be created, with danger for the speakers and power amplifiers, as well as serious sonic degradation.
The following information must be reviewed carefully and applied properly for the system to be immune of these problems.
The best sounding grounding schemes
The most difficult and important connection in a top quality system is the ground connection.
If not properly made, hum, distortion and instability may be induced. As for balanced connection, that Goldmund strongly disapprove, a bad grounding connection may literally ruin the lifelike dynamics that any really up-to-date system may reproduce.
The schematics recommended by Goldmund is known as the "Star System" as used in top measurement laboratories working on small signal levels.
In a Star System, only one central component (usually the preamplifier or multi-channel processor) is connected to the building ground (through the AC line connection or directly to an earthing post), and all other components are not.The ground connection is then properly made by the signal ground and if good quality coaxial is used for interconnecting the components (as the Goldmund interconnects and Lineal cables), the full system is totally shielded. For a top Goldmund system, the use of such high quality coaxial cable is mandatory for sound quality, perfect shielding and speed of transfer.
By simply lifting the AC wire ground connection of all other components, the star system is immediately built. However, for safety reasons as well as local regulation application, it is even better to link each component to the central unit by an additional very thick ground wire, connected to the yellow earth binding post of the components. On the central unit (preamplifier, ...), the black (signal ground) and yellow (earth) post may then be linkedIf the AC line ground is of the highest quality, the grounding system will improve sound and noise floor. If not, a real building earthing post must be used to connect the yellow post and the AC line ground must be lifted from the AC line too. Be careful that this type of installation must be made and controlled by a qualified technician to provide the perfect safety and quality.
The AC line polarity
From country to country, and even building to building, the AC line polarity may vary. The effect on sound of a wrong AC polarity is not common knowledge and this specific problem is usually neglected.
On a fast system like a full Goldmund system, the sonic effect of reversing the polarity of the electronic components may be far from negligible.
To properly adjust the polarity of each components, there are two different methods : the experimental approach, and the scientific approach.
To detect the proper polarity using the experiemental approach, the full system must be compared in sound quality with successively each component reversed. Usually, the sound is immediately more dynamic and open when the polarity is correct. To test a full system is a tedious and very long process, each component acting with the others and the number of combination being very high. Be patient. In a top sounding system, the result may be dramatic.
If you prefer to use the scientific approach, read our AC Polarity Measurement page. You need to have a very good high impedance AC voltmeter with high sensitibility. In some areas, small accessories may be acuired to help you detect by a simple measurement which polarity is the best. But we will recommend the full approach
To invert each component's polarity, a quite practical solution is provided by the Goldmund AC-Curator which has a separate polarity switch for each low-level output makes the choice very easy, even if the near-perfect isolation provided makes it far less critical. For components directly connected to a wall plug, the use of a special adapter may be necessary.
The Cabling problems
Choice of cables in an audio system has been very much pushed as a way to improve any system in the press during the last decades. No need to come back on the fact that cables sound different. But what seems less understood is that the sound of a cable is very dependent of the connected components. There is no such thing as the absolute best cable for any type of connection.
In a Goldmund system where the speed of the signal is mandatory and kept very high throughout, coaxial is the only reasonable solution. It is not only the best solution for digital cables, or for interconnect, but is also the best solution for speaker cables.
In addition to the speed that coaxial may help to maintain, the perfect shielding that the best ones may provide is mandatory to avoid oscillations.
But there are also some additional tricks.
To insure a perfect stability in a system, the input cables (interconnects) of an amplifier must absolutely be kept apart from the output cables (speaker cables). Otherwise the high frequency antenna created by the shielding ground of the speaker cable may, if the system is imperfectly earthed, radiate to the ground of the input cable and create a high frequency loop, inducing oscillation of the power amplifier. Run the cables separate or cross them at right angles and your system will be totally immune to this effect.
More, when you use long interconnects to a stereo or multi-channel power amplifier, run them close together, to avoid creating ground loop which will induce hum or buzz if you are in a bad RF area.
And finally, when the choice exist, and you are using Goldmund interconnects and Speaker cables, choose to run longer Speaker cables and shorter interconnects rather than the opposite. Loss of quality is faster in long interconnects than in long Goldmund Speaker cables because the carried impedance is higher.

Great info! Very sane! To keep all things fair and balanced I feel compelled to contribute some insanity or in the direction thereof.
I drove myself crazy trying dozens of powercables, and realized, as you stated, that the "best" powercable for one of my systems was not the best for another one. Maddening, especially if you dont have a real life! Now, and potentially contrary to the recommendation of shielding, I consistently found shielded powercables to sound dull, especially noticeable on various tubeamps. I did not find this to be as apparent or existing on digital and ss.
In regards to Job 225 I also found my preferred powercable with minimum shielding sound superior to my shielded options. So, so, maybe I still should try Jobs own cable since it was designed for this specific amp. I guess you never know until you try. But first, I will upgrade the fuse. In regards to my earlier personal comment about not having a real life, I say, "real" life without this obsession is clearly overrated.

Thanks to reading this thread, I have just replaced the stock power cord on an Auralic Vega DAC with a Job Sweetcord. The resulting improvement in musicality was immediate and profound. I am finding myself tapping my feet on every track. This combination is very engaging and I am enjoying the system more that ever.
My hypothesis is that the AC Curator circuit is largely responsible for the difference. The resulting noise reduction seems to have improved the pace and timing of the music, increased resolution and lowered the noise floor a considerable amount.

I have ordered a second Sweetcord to be used on my NAD M50 music server (which is connected to the Vega with an AES/EBU 110 ohm Spdif cable). I hope to enjoy a similar improvement in the sound quality. If you are interested, I will be happy to report on the result.

It seems the Sweetcord is a perfect match for digital electronics.

I think I might just get rid of my Audioquest NRG 4 powercord and get 2 sweercords when I order the Pre2 next week.

Sent from my SPH-L720 using Tapatalk

Originally Posted by Naim101

I think I might just get rid of my Audioquest NRG 4 powercord and get 2 sweercords when I order the Pre2 next week

I have several Oyaide Tunami cords but also decided to try the Sweetcords that the power supply designers worked with .. to obtain the factory performance baseline to start with.
.

joeinid,
Did you get a chance to try and care to comment on the Audio Horizons fuse you were talking about earlier?
Thanks Jon

Is anybody using coaxial 'Goldmund style' or their OEM cabling with their Job 225 either input or speaker side and care to comment on their experience with it .. ?

FYI- Audio Magic now has an improved Super Fuse! ; )

Originally Posted by Spla'nin

Is anybody using coaxial 'Goldmund style' or their OEM cabling with their Job 225 either input or speaker side and care to comment on their experience with it .. ?

I'm very curious about how to obtain Goldmund/JOB/Stellavox cables myself.

For what it's worth, I've noticed that the JOB is very sensitive to interference from interconnects. I've had better luck using cheap interconnects made from RG-6 (bulk coax cable) than I have from audiophile (Audioquest) or 'pro' (Canare, Mogami) interconnects. A lot of us early adopters of the JOB had ground loop problems with first-batch JOBs no matter what we used with them. (And, yes, JOB/Goldmund resolved the problem swiftly and brilliantly.)

Originally Posted by Lutfisk

Great info! Very sane! To keep all things fair and balanced I feel compelled to contribute some insanity or in the direction thereof.
I drove myself crazy trying dozens of powercables, and realized, as you stated, that the "best" powercable for one of my systems was not the best for another one. Maddening, especially if you dont have a real life! Now, and potentially contrary to the recommendation of shielding, I consistently found shielded powercables to sound dull, especially noticeable on various tubeamps. I did not find this to be as apparent or existing on digital and ss.
In regards to Job 225 I also found my preferred powercable with minimum shielding sound superior to my shielded options. So, so, maybe I still should try Jobs own cable since it was designed for this specific amp. I guess you never know until you try. But first, I will upgrade the fuse. In regards to my earlier personal comment about not having a real life, I say, "real" life without this obsession is clearly overrated.

The Sweetpee AC cable sucks!! Go buy a good AC cable for the Job.

Thanks W,

The Sweet is no match for a Stage 3 or Dynamic Design AC cable. The difference is huge! but $200.00 vs $3.7K is huge also. So in the end the Sweet rules for almost all.

Originally Posted by 2glory

The Sweetpee AC cable sucks!! Go buy a good AC cable for the Job.

The Sweet is no match for a Stage 3 or Dynamic Design AC cable.

The difference is huge! but $200.00 vs $3.7K is huge also. So in the end the Sweet rules for almost all.

Just few objective observations would give your post / personal rant a just a sniff of validity .. whats your Dranetz meter (or better) tell you ?

Has anyone compared the Job 225 to Goldmund Mimesis SR Mono amps?
I used to have them and a SR Evo pre and really liked them ......but....after the divorce they went to the guys with the shiny suits

Thanks

Robert

Originally Posted by Spla'nin

The Sweet is no match for a Stage 3 or Dynamic Design AC cable.


Just few objective observations would give your post / personal rant a just a sniff of validity .. whats your Dranetz meter (or better) tell you ?

Spla,

Nice skull you have there. So much more room for extra Brain matter.

Sweetpee is a good cable but has limited abilities where as the two listed AC cables I wrote about allow the Job 225 to fully function at its peek performance that with cause it run with the bigger boys!

No war here please. No need to defend Sweetpee! Had it and liked it! so I will agree with any positive comments about it. If you want to crank out a lot more from this amp try a DD/Stage 3 cable. Next to these 2 AC cables it sucks.

Hi all, first post. I signed up to ask this question:

Anyone have any experience with the Job 225 and Quad 57's?

If I thought it would work I'd order one in a New York minute.

All comments welcome.

First post - I tried to post this before but it didn't show up?

Anyway - anyone have any experience with this amp and the Quad 57?

I would order one pronto if I thought it was a safe combination....

Joe

When that speaker was in production the recommended amp by Quad was their 15wpc Quad II amp. If I remember correctly they prefer current over watts.

Originally Posted by Jack

Joe

When that speaker was in production the recommended amp by Quad was their 15wpc Quad II amp. If I remember correctly they prefer current over watts.

You could easily blow up the 57s with the power of the Job amp.

Your right as you could with most high power amps, but with moderation of the volume control it would work with the right preamp. High gain models need not apply.

Originally Posted by Jack

Your right as you could with most high power amps, but with moderation of the volume control it would work with the right preamp. High gain models need not apply.

If you want to hear the 57s at their best, listen to them with the tube amps that were designed to be used with them.

I agree, I have a Music Reference RM-10 they would be perfect with!

Originally Posted by Jack

Your right as you could with most high power amps, but with moderation of the volume control it would work with the right preamp. High gain models need not apply.

Twenty years ago Quad devised what they call a 'clamping board' which limits the amount of voltage the panels can see.

So it's not how much power, it's how stable into a load whose impedance varies pretty drastically by frequency.

It's hard to predict what will work. The Belles amps...no. Heed? Yes. Rogue Sphinx, yes, some small class A amps (I'm looking at YOU, Monarch) no.

Originally Posted by 2glory

The Sweetpee AC cable sucks!! Go buy a good AC cable for the Job.

I bought Gary's old Sweetpee and had it Cryo'd along with my Itube. What a difference that made. The Sweetpee now is easily 2 notches better in the SQ than before, more detail and bigger soundstage while more natural sounding. The Ttube is easily 3-4 notches better. That was the best 20 bucks I ever spent for a tweak.

Another trick that helps break in is to get the adapter & put it inline on the refrigerator cord for a couple weeks .. or you could beg borrow or appropriate a cable cooker .. but everybody has a frig ..

Originally Posted by ozarktom

I bought Gary's old Sweetpee and had it Cryo'd along with my Itube. What a difference that made. The Sweetpee now is easily 2 notches better in the SQ than before, more detail and bigger soundstage while more natural sounding. The Ttube is easily 3-4 notches better. That was the best 20 bucks I ever spent for a tweak.

Originally Posted by KLH007

Allen, Besides the blacker background, are there any other parameters where the JOB betters the Rowland, dynamic excitement, detail/transparency, woofer control/bass accuracy, treble extension/air? I wouldn't expect it to be overall better, but it might sneak in a small victory somewhere. Has anyone used speakers with low impedance dips that test the JOB's claim of "unconditional stability, it can drive anything"? The little amp that could is gaining traction as an unbelievable value, I look forward to many more new owners posting their findings as their JOB 225s break in.

Where did JOB claim 'unconditional stability, it can drive anything'?

I didn't see anything like that on their webpage.

The Jobs webpage just got updated with a pic of the new preamp.

I can't post a link because I don't have ten posts but google is your friend.

Thanks, Joe.

When I was at this webpage last week the preamp had a 'add to cart' button next to it and now it's a 'view cart'.

So.... are these for sale or not? Anyone ordered one?

Originally Posted by ls35a

So.... are these for sale or not? Anyone ordered one?

They are hand assembled & shipped from Geneva and produced in small quanities / batches .. when they have a batch ready for sale, they then allow sales via paypal and then disallow sales when that batch has been sold. Friday early Geneva time is when the sales usually begin, and depending on supply & demand, sales will end in hours or days until the next round. Pre2 sales were available for a time this last Friday until the production run was sold .. several were ordered by members here!

Originally Posted by Spla'nin

They are hand assembled & shipped from Geneva and produced in small quanities / batches .. when they have a batch ready for sale, they then allow sales via paypal and then disallow sales when that batch has been sold. Friday early Geneva time is when the sales usually begin, and depending on supply & demand, sales will end in hours or days until the next round. Pre2 sales were available for a time this last Friday until the production run was sold .. several were ordered by members here!

Understatement of the day: I'm looking forward to hearing how people like this PRE with the 225!!!!

Sold out.

Are u $@#/^^ kidding me? Its sold out in 1 day? I was gonna order mine tmr morning at work..

Sent from my SPH-L720 using Tapatalk

Apparently it's available again.

Originally Posted by soundArgument

Apparently it's available again.

I hate to buy the first production run of anything, but this is tempting me to break that rule.

So what preamps are people using to good effect with this amp? I'm aware of the 'high gain' problem which means a lot of preamps don't have much useable volume control.

Is anyone using the:

1) Conrad Johnson Classic
2) DSPspeaker

??

Originally Posted by ls35a

I hate to buy the first production run of anything, but this is tempting me to break that rule.

So what preamps are people using to good effect with this amp? I'm aware of the 'high gain' problem which means a lot of preamps don't have much useable volume control.

Is anyone using the:

1) Conrad Johnson Classic
2) DSPspeaker

??

I'm using the Wyred STP/SE with very satisfying results and I am reluctant to give up some of its' features for the new Job. BTW- I assume the toggle switch is for switching inputs?

Jeez. What a giant thread ... sorry to jump in late.

Fun amp. Great price/performance ratio. Not a universal can opener, though.

Sorry to be something of a tease, but I do have a review of the JOB 225 coming out, whenever this Newport coverage ends.

Originally Posted by joeinid

as long as the speakers are fairly easy to drive, the Job can be outstanding.

I think this nails it precisely on the head.

The other part, then, is the synergy with the speaker. I wouldn't, for example, shoot for a loudspeaker that veers toward the neutral or bright, or recommend it for folks that tend to gravitate toward "tone" and tubes ....

Caveats in place, it's a solid performer.

Joe

I agree about the easy to drive part. As much as I like the Job, I have found that with the Treos' the Odyssey Khartago Extreme has more grip with the bottom end. I switch back and forth every couple of weeks between the Wyred/Job and the Anthem/Odyssey. I'm not sure that one of Klaus's Kismet designs in the Khartago case might give the Job all it can handle and be easier to drive by a larger number of preamps. It would certainly have more current capacity with well over 120,000 AuF. If you have never heard one, you might want to take one for a spin. The price would be about the same with a 20 year warranty. I have had one of Klaus' amps in house for over 15 years and would not be without one.

Originally Posted by RPM-123

I'm using the Wyred STP/SE with very satisfying results and I am reluctant to give up some of its' features for the new Job. BTW- I assume the toggle switch is for switching inputs?

I had a STP/SE running a Rogue Atlas a few years ago. Was an amazing combination, wish I'd kept it. The STP/SE is particularly good....

The Wyred does a lot of things right plus the convenience factor. If you can find one used like I did and the rest of you gear meets it's parameters it is a really good preamp.