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View Full Version : After the Tirna upgrade for 7520, has anyone found sibilance in headphout out?



theone999
24-12-2009, 10:47
A while ago, I sent my 7520 in for the Wolfson chip and 4562 op-amp upgrade. shortly after, I sent my custom in ear monitors in for repair as it had been lying around broken for a while.

I am getting quite bad sibilance while plugging my iems into the 7520. I sent my iems in to be checked over by lab technicians, but they found nothing wrong.

So have anyone noticed the headphone out displaying sibilance after the Tirna upgrade?

Covenant
27-02-2010, 08:39
Yes most definitely, I get the same problems with the headphone circuit.
I had put this down to using cheap cans however these have had a filter installed plus some other mods. Despite this sibilance remains an irritating problem which is not noticable through speakers.
Anyone else with the Wolfson upgrade noticed this? Any thoughts Stan?

StanleyB
27-02-2010, 08:55
Try a different opamp to the LM4562NA if it is a TC-7520.

technobear
27-02-2010, 21:29
My Beyer DT531 are quite bright and sibilant and spitty when driven by the Caiman. Again, it is not noticeable through the speakers.

The phones sound great so long as I avoid female vocals :rolleyes:

theone999
28-02-2010, 00:56
Ok, glad that we have some sort of consensus here and it wasn't me that was dreaming it.

Stan, would you care to suggest a particular opamp yourself for a TC7520 with the Wolfson chip upgrade? I do not have any opamps lying around.:(

Though as a first thought, maybe the opamp in the original TC7520 would be a better match with the Wolfson than the LM4562? (Which opamp was that again?)

leo
28-02-2010, 08:57
Just remember LM4562 doesn't like driving capacitive loads, some headphones and their cable can be high capacitance so may cause it problems

technobear
28-02-2010, 11:23
Just remember LM4562 doesn't like driving capacitive loads, some headphones and their cable can be high capacitance so may cause it problems

Interesting. I have several ear-buds of varying proficiency here and they all emphasise sibilance to a degree but the Beyers do it the most.

I generally only use the phones to double-check that bad sounds are coming from the CD and not the system so I'm not worried.

Covenant
28-02-2010, 12:45
Just remember LM4562 doesn't like driving capacitive loads, some headphones and their cable can be high capacitance so may cause it problems

I tried the OPA2132 last night and it sounds pretty much the same as the LM4562. What about the AD862? (or is it AD826:mental:)

Gazjam
28-02-2010, 12:47
826

not much to offer here as I dont even have an Opamp in the headphone board, nevermind own a set of cans...

Covenant
28-02-2010, 13:16
Gaz, can I be so bold as to suggest you get yourself the HD681's? I bought them to see what the fuss was about, not being a headphone user I figured that for under £20 they would be handy for late night listening and would stop the rest of the household moaning about the volume.
I have been suprised how foot-tappingly fun they are and use 'em a fair amout of the time. With the filter and velour pads added they must compete with £150 cans.

StanleyB
28-02-2010, 13:31
Looking at my Caiman development notes, I noticed that I made an entry indicating that the removal of MLC5/6 had a positive effect on controlling sibilance. I also made another entry, noting that sibilance was more apparent on ripped files than from a CD. Compressed files had the worst sibilance.

These are just my notes, so don't take it as cast in stone.

The Vinyl Adventure
28-02-2010, 16:20
Gaz, can I be so bold as to suggest you get yourself the HD681's? I bought them to see what the fuss was about, not being a headphone user I figured that for under £20 they would be handy for late night listening and would stop the rest of the household moaning about the volume.
I have been suprised how foot-tappingly fun they are and use 'em a fair amout of the time. With the filter and velour pads added they must compete with £150 cans.

im glad they worked out for you in the end jerry, i too like them quite a lot, and with the filter in fact prefer them to my grado sr125's

theone999
28-02-2010, 20:12
Looking at my Caiman development notes, I noticed that I made an entry indicating that the removal of MLC5/6 had a positive effect on controlling sibilance. I also made another entry, noting that sibilance was more apparent on ripped files than from a CD. Compressed files had the worst sibilance.

These are just my notes, so don't take it as cast in stone.

Hmm, but the sibilance issue do not affect the speakers. In fact, I am very happy with the sound out of the speakers from the RCA out at the back of the DAC. So I do not wish to tamper with that.

The problem is restricted to the headphone circuit. But I have also noticed something. The free earbuds that came with my Nokia mobile phone is totally unaffected by this, while my custom made reference IEMs (ACS T2) are rendered unlistenable on 50% of tracks.

I have a mix of FLAC and mp3 formats. The format makes little difference if the mp3 was ripped well. Try listening to some Celion Dion through the headphone out and one will quickly find out the problem.

Covenant
28-02-2010, 20:19
I wouldn't read to much into the sound from your free earbuds.
I would try putting back the original op-amp and see what happens. If the sibilance goes then you can try some of the more high quality ones.

Gazjam
28-02-2010, 21:06
Gaz, can I be so bold as to suggest you get yourself the HD681's? I bought them to see what the fuss was about, not being a headphone user I figured that for under £20 they would be handy for late night listening and would stop the rest of the household moaning about the volume.
I have been suprised how foot-tappingly fun they are and use 'em a fair amout of the time. With the filter and velour pads added they must compete with £150 cans.

Hey Jerry,
I rememebr us talking about these before...wasnt there three different kinds, depending on what "tone" you were looking for or something?

Is there a best one to go for?
And someone else (?:)?) mentioned that he had his headphones sent to Holland I think it was to get them modded?

Dont want to hijack the thread, but a wee bit of info on that would be good, particulalry as Hamish's Grados are supposed to be really good phones.


Thanks.

Covenant
28-02-2010, 21:18
As you say-we dont want to hijack the thread so I will send you an e-mail with some details. :)

The Vinyl Adventure
28-02-2010, 21:44
I should point out that if I was asked which are better I would say the grado's, they are more real sounding, my superlux are quite sweet and popy sounding by comparison. Mine are the standard ones

technobear
28-02-2010, 21:44
Errm... my earlier judgment of the Caiman/Beyer performance was incorrect :o

These phones used to have a piece of black foam covering the innards. This had rotted and recently fell apart. I didn't give it much thought as I assumed that it was just cosmetic. Errm.... no it wasn't :doh:

So as a stop-gap I have cut a circle of Kleenex and inserted it into each ear cup. The sound balance is now much better and the sibilance, while still more than I get through the speakers, is no longer particularly excessive.

Sorry if I misled anyone :oops:

theone999
28-02-2010, 21:57
I wouldn't read to much into the sound from your free earbuds.
I would try putting back the original op-amp and see what happens. If the sibilance goes then you can try some of the more high quality ones.

Tirna never sent back the original op amps, will have to ask them, I guess. What was the original opamp anyone?

leo
28-02-2010, 23:47
I tried the OPA2132 last night and it sounds pretty much the same as the LM4562. What about the AD862? (or is it AD826:mental:)

OPA2132 gives me a headache anyway tbh:)

I've not had any problems with headphones so far with this dac tbh but I use an external amp for headphone duties mainly because I have more than one source. currently no chip is in the dacs HA socket. I'll try re-fitting one of the op-amps in the socket and see how it goes.
I'm currently using THS4032 in the dacs output stage (left socket)

I have Sen HD250 linear II, HD650 and AKG K701

leo
28-02-2010, 23:52
Tirna never sent back the original op amps, will have to ask them, I guess. What was the original opamp anyone?

NE5532 in the 7520, actually not a bad little chip and certainly don't deserve all the slating they get imo, obviously there is better spec ones out there now but the NE is still used a lot in pro gear

ZebuTheOxen
01-03-2010, 12:21
I've had the Wolfson upgrade done by Tirna.

It's important to take out the MCL 5/6 caps because it makes the whole thing sound wrong - probably the sibilance mentioned initially. After a few months of worry about subsequent distortion I was getting, it turned out to not be the amp or headphones but the songs themselves.
The levels on many of them are far too high and distort, even some remasters (Led Zep's 1990 effort springs to mind) has random passages which are over compressed.

Replay Gain is definitely worth looking into if your source is PC-based. This helps level out volume and reduce the issue of distortion from source.

On properly mastered songs the setup sounds fantastic.

theone999
01-03-2010, 17:37
I've had the Wolfson upgrade done by Tirna.

It's important to take out the MCL 5/6 caps because it makes the whole thing sound wrong - probably the sibilance mentioned initially.

Then why do I have no problem with my speakers run out from the RCA out even while playing the same tracks? Sibilance is not a problem there.

*note* I use the "variable output RCA", ie I can change the volume with the 7520. I do not use the fixed outs.