Headphone Amp Tweaking idea,s Pleas

[colin.hepburn]

Headphone Amp Tweaking Idea’s Pleas

I have just finished my Choke scratch Built PSU Built up from solen polypropylene Caps and mills resistors and Am now looking to improve the Amp I have updated most parts in the Amp this Project is of a learning exesize so cost should be kept low
Parts Upgraded
To
Alps Volume Pot
R2a/R2b PRP
C2a/C2b Os-com
R4a/R4b Mills
C3a/C3b Black Gate
Thinking of the Shunt Pot Volume Control
The Amp Sounding good But More ideas would be welcome


http://www.world-designs.co.uk/forum...1&d=1156875293

[Primalsea]

You could have a look at the Headwize website. IMHO I think that crossbleed between channels is excellent. There is detailed info on the site.

For a more conventional tweak a switched attenuator would probably be a good choice.

You could also go for channel matching controls. A balance pot is one option, the other is a multi turn pot on each channel prceeding the volume pot. These can be adjusted to correct the imbalance of teh current volume pot.

[colin.hepburn]

Hi Primalsea
Thanks for you reply
yep switched attenuator or the shunt pot on here would be good not sure about crossfeed tho thinking more of battery bios if i can do it with this amp

[colin.hepburn]

Hi All
I have not been all that happy with the sound of my Headphone amp I found it to be tiring to listen to so over the three days of tweaking it added three more electrolytic caps to the PSU which is made up of choke solen polypropylene this made improvements giving more depth
But still keeping the speed but still sounded shut in and masked the detail
I then removed the 2uf polycarbonate cap that I had in to bypass the 33uf black gate
I now had the depth speed clean clear detail back but now I can here the sonic signage of the black gate ok so replacing the bypass Cap this time with a 2.2uf soniqs sax from WD
The effect of this was jaw dropping lifting the amp to new heights
After 24hours running in the soniqs caps I felt the detail was little bit lacking so I replaced the 2.2uf with 0.1 soniqs this has worked a treat I then changed the resistors in the Shunt Pot Volume Controlto 82k A.N tantalum giving much better control range This Amp now just seems to grab the music and hold on delight to listen to







Ok at this point some would consider the amp finished well yes it is but as this amp is a good learning curve for me I still want to try and take it up to another level.
I have though about Dual mono PSUs and better output transformers than the Hammond 119DA http://www.hammondmfg.com/collins.htm I have also considered the Sowter Type 8665 http://www.sowter.co.uk/ can the sowters transformers be dropped start in I would welcome you help on this and other improvements I can do to this Amp
Thanks
Colin

[BOONDI]

Originally Posted by colin.hepburn

I now had the depth speed clean clear detail back but now I can here the sonic signage of the black gate ok so replacing the bypass Cap this time with a 2.2uf soniqs sax from WD
The effect of this was jaw dropping lifting the amp to new heights
After 24hours running in the soniqs caps I felt the detail was little bit lacking so I replaced the 2.2uf with 0.1 soniqs this has worked a treat I then changed the resistors in the Shunt Pot Volume Controlto 82k A.N tantalum giving much better control range This Amp now just seems to grab the music and hold on delight to listen to

Colin

Hi Colin, all.....

Colin, if you can hear the BG sound then surely they are degrading the signal?
Is the effect something you like hearing?

The reason I ask is because I am in the middle of trying a few of the cheaper "Audiophool" brands of capacitor in my phono, and do not want to use anything that is blatantly coloured......

Comments please......

[colin.hepburn]

Originally Posted by BOONDI

Hi Colin, all.....

Colin, if you can hear the BG sound then surely they are degrading the signal?
Is the effect something you like hearing?

The reason I ask is because I am in the middle of trying a few of the cheaper "Audiophool" brands of capacitor in my phono, and do not want to use anything that is blatantly coloured......

Comments please......

Hi Boondi
The sound I’m hearing is good from the BGs it’s just that you can tell that you are listing to an electrolytic cap, but bypassing it sweetens it up

[colin.hepburn]

Hi All
Can I improve this headphone amp and Psu as this amp is an ongoing learning curve for me I am interested to try a few things
First is this choke working as it should in this psu 30H 595R 40mA I want to try choke tuining what value of cap is required for this choke plus I want to try plate loading the 12ax7 and/or 12B4a or both would the Hammond 150H 8mA work with the 12Ax7 or can you recommend a choke for the 12ax7/ 12b4a See amp sch http://www.wduk.worldomain.net/forum/attachment.php?attachmentid=708&d=1172003535 And PSU Sch http://www.wduk.worldomain.net/forum/attachment.php?attachmentid=709&d=1172003586
Thank for the advice
Colin

[Black Stuart]

Hi Colin,
I have to say straight out - I don't like Solens, they sound grey to me. I have a Bada PH12 hybrid h/amp and it is full of Solens. I intend to replace the lot with Silmics, which give 95% of the BG performance but are so much cheaper and don't need to be burned in again if a piece of equipment is'nt used for a while. In fact in cathode bypass role, the Silmics are much better than FK BGs in both the KEL34 and KAT88 amps.

I changed out a pair of 1uFs, the first in the signal path for Mundorf-Audiophilers and the difference was wonderful. I then changed out a pair of 2.2uFs and again a big difference.

The Mundorf-Audiophilers are completely underrated probably because they don't cost a lot. They are compact and easy to fit in tight spaces.

Boondi, do try these Audiophiler caps - think PIO but much better bass and tighter, with a really sweet top end. Perhaps the best way to describe it is, that it combines the best of PIO and polyprop.So impressed with these caps am I that I have ordered enough to change out some AN alu PIOs in the KEL34 and KAT88 and I shall try a pair of 2.2uFs in the phono stage.

Colin, what kind of power cord do you use - standard PCs are ****, especially used for things like h/amps and CDPs. I bought a 500ft roll of US mil. spec. wire made by Rechem and use this for all PC construction now. It is rated to 1200V and is silver/plated copper of the highest spec. - cables do make a difference and when I replaced the supplied PC for one using this mil. spec wire within two days the Bada was alive, breathing, where before it was just 'OK'. For me it was a bigger change doing this than the caps or shunting the pot, simply because it allowed the subsequent changes to show through far better.

[colin.hepburn]

Hi Stuart
Yes I agree on the solen caps I used these in the new choke psu I built but there are only low value 22uf I added large rubycom elect across the solens as reservoir caps his removes the solen greyness’ but keeps the speed of solens in the cathode bypass I have Oscons caps blows way the BGs I my view output BGs are bypassed with a sax 0.1uf cap from WD a great cap for the price resistors are A.N.tants and Mills mains is still the standard lead I have some overall screened mains cable to try I'm thinking of this cross feed thing have you tried this

[colin.hepburn]

Hi All
Well revisiting this amp again this upgrade will have a bigger PSU and anode choke on V1 plus anode choke or C4S Kit on V2 and ASC Oil caps on C2 the output there are no Elect Caps in this amp anywhere not even in the PSU and it sounds very good driving 300 ohm sennhizer HD650s so why change it I here you say well the amp is also a learning curve for me as well as experimental given that you can clearly hear the sound of different components it’s the ideal platform to work with here is the Sch as last upgraded Version
The second Sch is the intended upgrade however I'm not sure which way to go on V2 the 12B4a i.e. anode choke or a C4S if choke what spec would best suited to the 12ba4 HT @300volts
All Hammond chokes from Phil @ bluebell to keep cost down
Can Anyone pleas advice on choke spec for V2 and on any other ides you think may work well
Cheer's
Colin