Thanks Yeo. My life is greatly enriched by the beautiful sounds that you & VT4C & Paul Hynes & other forum members have helped me to bring into my home. I am very grateful.

I'm a bit late to this thread (not been around for a while), but just wanted to say...

yes! they are good!!!! They are very, very good.

See my post here:

http://diyparadise.com/forum/index.php?topic=1242.msg13167#msg13167

The buzzing problem that whole thread was about disappeared when I implemented the Music Rail in place of my Black gated PH PR3GAP. Don't understand why - the PH sounded brilliant and worked faultlessly with different sources to the Buffalo/Sowter setup.

Anyway, Charlize 2 powered through Bybee Music Rail sounds as good as through PH. Ever since then I've not pursued further tweaks to my system. It sounds better than I ever thought recorded music could sound. I don't really think it could get significantly better. I stopped DIYing. I lost the hunger to improve anything. The search was over. I just want to listen to music now.

 

Thanks VT4C, I guess I gotta give it a try... unless of course you can tell me how to make Charlize 2 act like a Charlize 1 with Biascap mod?

No worries if not though. I appreciate your input.

Dave.

VT4C,

Would you guess that if my biascap modded HLLY board works with my Sowter output DAC without buzzing, then Charlize 1 would work also (with biascap mod applied)? I know you cannot guarantee, but best guess?

I weakened last night and tried to buy a Charlize 1 in the diyp store. I am yearning so much to hear that Charlize magic with this DAC. HLLY sounds very very good (especially with Bybee music rail for PS), but doesn't compare to Charlize's grace and beauty.

But hey diyp guys, I couldn't remember my password for the store and the function to email it to me didn't seem to work (tried a few times). Is this fate trying to tell me something?

Hi,

I'm wondering if anyone has a Charlize 1 board lying idle and wants to sell it. I know they are for sale in the shop currently but I need one cheap for an experiment that I am not sure will work.

It does not need to have any input caps or reservoir caps onboard, but does need to work.

If you have one then please let me know how much you want for it with shipping to the UK.

Cheers,

Dave

OK, well at the risk of boring everyone I thought I'd mention where I'm heading with this.

I reread my post and realised that the difference between the two setups (doh!) was connecting signal gnd from Sowter transformers direct to pin 14 to TA2020 on HLLY but not Charlize. Obviously. So I tried connecting direct to pin 14, but still buzzing. Not smart enough to  figure this one out it seems.

I decided to beef up the power supply used for the HLLY amp to see what performance I could get from it. I bought a Bybee Music Rail 15A version, removed the main cap from HLLY board and made a linear power supply feeding the Bybee then going to HLLY. Used a 12V 120VA transformer. Rectifed and with 2v dropped across the Bybee gives me 13.91 v measured which is great. Now this rocks. This is an excellent power supply for a TA2020 based amp (very low output impedance I believe)!

The sound quality I am hearing now is (obviously I guess) a big improvement again. I can't quite say it is as good as a Paul Hynes PR3 regulator - the bass I am hearing is not as good as my Charlize 2 with PH. (You also don't get the pleasure of buying from such a great guy as Paul and receiving his amazing support.) But the Bybee offers a moderately cheaper alternative for a great supply for a TA2020 amp (especially while the Parts Connexion sale is still on!). It is not a regulator of course.

Anyway, I'm thinking that before I will be satisfied I need to try a Charlize 1 with the Biascap mod applied. I am guessing that Charlize 1 will not buzz in the same way with my Sowter transformers feeding it. But because I am not completely sure this will work (and because I just quit my job ) I'm posting in the want to buy section to see whether anyone has a Charlize 1 in good condition that they want to sell for a reasonable price(?). I don't need any input or reservoir caps on board.

Thanks for reading.

My setups:

(Volume is controlled by firmware on the DAC)

By the way, I am not using a pre-amp (other than using a TVC previously). My problem seems different from the one that CoughinHK is having.

Hi VT4C,

Charlize is housed in a box made of walnut wood (see http://diyparadise.com/forum/index.php?topic=1062.msg10404#msg10404 for pics), whereas the HLLY amp board is just sat on some bits of MDF at the moment. So neither have RFI/EMI shielding. The power transformers for amp and dac are all housed >0.6m away in seperate boxes. The transport (Stello CDT100 which probably has SMPS) is nearby, but I have tried varying the distance of the transport from the DAC/amp with no variation in buzzing.

The lead between DAC and Charlize is about 1m, but they are physically only about 20cm away from each other when tested. HLLY is closer - I currently have HLLY sat directly on top of my open Buffalo chassis. Charlize has a Paul Hynes power supply fed by a 15v, 100VA toroidal and sounds absolutely wonderful with any other source. The HLLY is fed by a 12v adapter borrowed from a Yamaha keyboard.

When the DAC is switched off but the amp is on then this makes a big difference. With Charlize the buzzing gets considerably louder. With the HLLY a buzzing appears where previously there was none (or so small as not to be noticeable). With my limited knowledge I do not understand this - and am wondering whether this fact perhaps holds the key to the whole mystery (?).

Thanks for your continued interest VT4C. Because previously you suggested that the 2.5V bias was causing this problem and because the HLLY also has this bias, I keep thinking that the issue may be to do with Charlize and HLLY (BIASCAP modded) handling the 2.5v bias differently on the input section of the board? Because of the way I have mounted Charlize ( ) I cannot easily tell.

Cheers,

Dave

Hi,

A quick update on this...

I managed to reduce the humming quite dramatically by playing with a few things to do with grounding/psu. The biggest difference seemed to be by disconnecting the electrostatic shield on the power transformer (an R-core from Selectronic in France) from earth.

Now, with the Buffalo connected direct to Charlize the quality of music coming through is quite amazing - richer, fuller, more natural sounding bass than I ever imagined possible! Absolutely gorgeous midrange. But....

There is still a residual amount of humming. Could not get rid of it completely. It is just enough to ruin the complete enjoyment of the music, although to be honest I could almost live with it for the sound I am getting. But not quite.

So I tried connecting the Buffalo to another TA2020 board without caps. This is a HLLY electronics board that has been lying idle for a couple of years. I took the input caps/pot out, and connected my signal between pin 14 (Biascap) and the signal input. I think this is known as the BIASCAP mod. It works!

This setup gives some mild hum when the DAC is powered off (for some reason I do not understand). But with the DAC on there is no hum at all... and oh my giddy aunt does it sound good! Without the hum you can actually forget that what you are listening to is a stereo. The intimacy and richness of sound is fantastic. Really, really lifelike. This is the sort of presentation that I hoped to hear all along! Totally involving! Ace!

So I'm a happy man... except... for the knowledge that as good as this setup is, it would be better - much better - if I could get it to work with my Blackgated, Paul Hynes fed Charlize 2 without humming.

So I have one more little question: In order to go capless does Charlize 2 do anything different to what I have described doing to the HLLY amp? I guess this may be a trade secret. But would I be on the right track to think this?

Anyone?

Cheers,

Dave

Hi,

Thanks for all that input. Tying the signal input gnd to power gnd through a cap sounds an interesting idea, Coughin HK. You can see the 'input gnds' tied together on Charlize 2 board on photo here by the way:

http://diyparadise.com/shop/index.php?main_page=popup_image&pID=67

I have a largish isolating transformer (Keces 300W, got it 2nd hand) standing by to be used eventually, but have not tried it yet. Am struggling to find time at the moment to do any real playing around. And to make things worse have just taken delivery of a pair of TB W8-1808's given the Planet 10 EnABLe treatment! Too many toys, not enough time.

I will update this though when I have (hopefully) made some progress.

Thanks again,

Dave

Hi CoughinHK,

I'll have to look at grounding on the power supplies then, and see if I can improve things. I was thinking of earthing the DAC gnd as it is currently floating, but what you say puts me off - I take it no damage occurred to your amp?

'Gnd' (2.5v) on Charlize 2 inputs are tied together on the PCB, so this is unavoidable. I only run one wire out from there since both channels gnd is tied together on my TVC and now also on the DAC outputs (transformer secondaries) also.

Can you clarify the setup that you experienced your buzzing with - was it an ES9018 DAC and what trannies you used? Any detail on how you improved the PS grounding might be useful as I am not knowledgable in this area.

Thanks,

Dave

Hi,

Thanks for this link milen007 - this is a very educational read and does seem that jkeny's problem is very similar to my own. I've only made it through the first 4 pages but have to go to work soon so will need to return to it.

The 'ground' of my transformer secondary is floated to 2.5v as I understand it - this is done by Charlize's input 'gnd' (which is not ground at all, but 2.5v). The circuit that hums for me is therefore exactly that recommended by Pano, other than the presence of the 2.2K resistor across the primaries. Compare my first schematic above with Pano's second diagram below for connection to a T amp.

I will have to try some of the alternative suggestions in the thread, but was hoping to keep the galvanic isolation between DAC and amp, since this seems a positive feature to maintain.

Thanks again,

Dave

Hi vt4c,

OK... So I bet you can guess my next question...

Any suggestions for what I can best do about this?

The humming was not a problem with the TVC in the signal path (actually an autoformer so at max volume the signal would be going straight through, albeit with the autoformer parallel to the Sowter 3575 and Charlize's inputs). As I understand it the circuit would then be like in the attached rough schematic of one channel. Does this look correct and does it make sense that this removes the hum?

As ever, your patience is much appreciated!

Dave

Hi vt4c,

Thanks v. much for your reply.

I think the thing I am struggling with is how this input biasing translates to DC at the transformer secondary winding. Neither the transformer or the Buffalo circuit are tied to Charlize's power ground. So with one end of the secondary tied to Charlize2 input 'gnd' and the other end to +input is there definitely a DC voltage between these points?

In order for this to be the case surely it would mean that Charlize creates a DC voltage between her +input and her input 'gnd'?

Sorry to be a pain, but I am struggling to reconcile this with the limited knowledge I have accumulated so far.

All the best,

Dave