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Old 19th November 2008, 09:05 PM   #21
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Thats fair comment on the 840, it tries to light the leading edges, but does so at the expense of a bit of glare in the treble, modded it sings very sweetly. But still lacks some bite.
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Old 9th March 2009, 02:55 PM   #22
banause is offline banause  Germany
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Default hd 970 slight modding...

hi george,

i just bought a hd 970 (version 2 with sanyo laser)

i wanna use it mainly as a dac for pc-music.

can u give me some advice in a slight modding?
how about changing op275 to ad8620 and keeping 2134 in place??

maybe better caps in some positions?

thx ...marc
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Old 9th March 2009, 06:01 PM   #23
Javin5 is offline Javin5  Switzerland
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Default HD 990

Hi George

Have you ever got the HD 990 or the service manual? If yes, first impressions?

Kurt
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Old 9th March 2009, 09:45 PM   #24
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Default Re: HD 990

Quote:
Originally posted by banause
hi george,

i just bought a hd 970 (version 2 with sanyo laser)

i wanna use it mainly as a dac for pc-music.

can u give me some advice in a slight modding?
how about changing op275 to ad8620 and keeping 2134 in place??

maybe better caps in some positions?

thx ...marc

If I were to do a simple mod, yes it would be changing the OP275 for maybe a AD825 (my fav) they are singles so you would need 2 single to dual Browndog adapter board.


Quote:
Originally posted by Javin5
Hi George

Have you ever got the HD 990 or the service manual? If yes, first impressions?

Kurt
I had the HD990 here last month the first on into the country and
I was excited, until I picked it up, it was very light, I imdeatlty thought no they didn't!!!!! And yes they did, a dirty skinking rotten smp power supply and it's nearly double the price, they lost the beautiful Sony R-Core trany and nice power supplies and subsituted SMP junk.
I sent it straight back.
All it really has over the HD970 is quad diff dacs still the AD1955 just two of them, a little better SNR and DR figures that's all
Cheers George
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Old 9th March 2009, 11:51 PM   #25
Javin5 is offline Javin5  Switzerland
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Default HD 990 / HD 980

Thanks for the info. Too bad, for their top of the line model. On the other hand, you can't always say that something is bad because it uses an SMPS, not all SMPS's are created equal. I also think, you will see them more and more in new products. Appearently, HK has obtained a good SNR, despite the SMPS.

(a) Any thoughts or experience with the HD 980?

(b) I still have a HD 760. Have you ever seen this model and any thoughts on modding? Would this even be worthwhile? It has the PMD100 chip, which should be quite good. Not a very common player, it was only sold for a short time, as far as I know. I bought it at the time because it can decode HDCD. Most of the newer players don't support this anymore.

Kurt
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Old 9th March 2009, 11:56 PM   #26
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Default Re: Re: HD 990

Quote:
Originally posted by georgehifi


If I were to do a simple mod, yes it would be changing the OP275 for maybe a AD825 (my fav) they are singles so you would need 2 single to dual Browndog adapter board.

I had the HD990 here last month the first on into the country and
I was excited, until I picked it up, it was very light, I imdeatlty thought no they didn't!!!!! And yes they did, a dirty skinking rotten smp power supply and it's nearly double the price, they lost the beautiful Sony R-Core trany and nice power supplies and subsituted SMP junk.

I sent it straight back. All it really has over the HD970 is quad diff dacs still the AD1955 just two of them, a little better SNR and DR figures that's all
Cheers George
Hey Georgie Baby

Missed you Sunday 2 weeks ago when we had that blind amp shoot-out, it was a hoot. Was sitting next to Larry and said I missed you because it would have made it easier to do my score sheet, just look at yours and then reverse it. That got a laugh, but a good natured one. I just had trouble taking it seriously. The lower grade AKSA won and some modded DS (you know what DS stands for, right?, as is DSE) got second. Or was it the other way round? Think the Gryphon got last or second last, that was a bit of a shocker to all, I'd think. By the way, the Gryphon designer stole my brother's name: Flemming Rasmussen. Kid you not!

I've got somebody sending me up a 990 from Melbourne, might even get here this week. The smp worries me less than it does you, but I don't think it will be better than 970.

Re changing opamp, I know not all will agree, but I'd go for LM4562 (it's available from a company in Rhodes). I used one in a player as I/V converter and was impressed (it was a Rotel RD-990 - well worth finding cheap), even if that kind of opamp thing is not my cup of tea, but that was what he could afford.

But what should be tried on 970/990 is hot-wiring to a separate RCA sockets, via a coupling cap, straight of one side of the I/V converter. There may be some DC there, hence the cap. That is what I did with the LM4562/Rotel. For what was involved, it was terrific in $ terms. You may get a little less than 2V RMS out, but in this case I got near 1.8V - no probs.

That and Terra Firma, and you have a lower cost route.

For those who read this and don't know what Terra Firma is:

customanalogue.com/terra_firma.htm

http://www.audioasylum.com/audio/dig...14/142994.html

Joe R.
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Old 10th March 2009, 12:11 AM   #27
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The HD990 had the sound that typifies to my ear the sound of SMP, which was a thinner lifeless sound, good still in dynamics but in a squeezed and shot out of your speakers kind of way. The HD970 flowed out, sounding larger and more effortless.
In my opinion SMP's have no place in source equiptment yet. The only place they have been done properly that I've seen are in the massive Halcro DM88 power amps, at that end of the of the chain it's ok, but keep the dirty radiating stuff out of source equipment until they can better it.
Harman only used it to save money, it cost one third the price to manufacture the HD990's smp power supply than it did the HD970's R-core linear supply, yet the price has almost doubled, go figure.
They are just resting on the good name and publicty the HD970 got and decided to clean up on the HD990.
.

Cheers George
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Old 10th March 2009, 02:28 PM   #28
banause is offline banause  Germany
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Default terra firma?

hi joe,

thx for your advice. sounds good to me to use the LM4562 because they are cheap and i do not need adapters.

but i'm still not really sure about terra firma.
is it a clock-module? how much does it cost?

thx ...marc
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Old 10th March 2009, 11:38 PM   #29
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Default Re: Terra Firma?

Quote:
Originally posted by banause
hi joe,

thx for your advice. sounds good to me to use the LM4562 because they are cheap and i do not need adapters.

but i'm still not really sure about terra firma.
is it a clock-module? how much does it cost?



thx ...marc
Hi Marc

Yes, it's a low cost solution IF you are stuck with opamps. Re Terra Firma, contact Vacuum State just or the border to Switzerland in Schaffhausen. This is their web site:

www.vacuumstate.com call them or email them. Ask Vacuum State for Terra Firma "Lite". Prices are here:

http://vacuumstate.com/fileupload/Ne...Feb_2009_1.pdf

You can buy and it fit yourself, but if they do it, they can do the other suggestions I've made as well and it will benefit from a "program" that I can direct them to do.

TF is about reducing the worst kind of jitter - so it takes the form of a powered clock module a la LC Audio, SuperClock and all those others available. But TF goes way beyond what they do by giving the clocking extreme stability that is unmatched by our competitors. The proof is in the listening - it makes digital sound much less digital or more like analogue.

They could also, with my direction, fit LM4562 and extra RCA Sockets on the back panel, wiring directly to the LM4562 used as I/V converter. Based on the Rotel I did, I can be confortable in saying that the player you'll get back will be stunnnnn-ningly better in every respect. I have to say, the LM4562 is the opamp I want when I don't want an opamp but must still use one. A variation of what we down here call a "Clayton's".

An example of a Clayton's: "The mistakes we make are genuine, otherwise we wouldn't be making them." Comprehendo?

Cheers.

Joe R.
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Old 12th March 2009, 05:12 PM   #30
banause is offline banause  Germany
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thank you joe - j'ai comprend!

but why does h+k put in so many parts for the output stage if it sounds best when directly going out of I/V ???
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