Completing last mod, hell or heaven?

[versil]

Hi,
yesterday I finished my third mod-operation. Soldered six UF4007 bypassed with 10nF caps, desolder my two 10 µF MUNDORF input caps and jump over with a wire and
changed the original 470 nF cap (upper PSU-board, the red sweetie) to a EPCOS MKP 470 nF, 1000 V, sorry, I have only these big 1000 V one on hand, I overcome the problem by using insulated wire and sticking the capacitor to the board.
The result……..a further noticeable significant sound improvement: clearer voices, more open sound-stage and sparkly heights……I am in heaven now, but what happens with the bass?

The bass sounds very slim, he is very controlled, absolute present and I miss objective nothing. Only these powerful “bang” has gone. Is hard for me to explain, what I mean is these “head-shaking” pumping, the power.
Did I something wrong or have I acclimate with the new and “accurate” bass. Now I am in hell and alienated.

Please any comment would be appreciated,

thanks, Henry

[aurum]

Maybe its time to have a look at upgrading your valves. The stock JAN's are a bit thin sounding.
Or: Put the Mundorf's back & have another listen

regards
Ian

[versil]

I put back the two MUNDORF Caps.........and the sound at the lower frequency turned back to what I knew. Very powerful bass but the height-transparency decreased.

The bass from the foil-caps plus the heights from the wirebridge would be quite safe the best (IMO).

Hard to believe but it is a fact.

Arcam CD93, X-PSU with X-Can V2 (maxed out), HD600 with Cardascable.

Has everbody a statment for that electroacoustic behaviour. Why is the bass in bad case without high-quality-audio Input-caps in the signalpath??
Could it be compansate by jump over the output caps (without Input and outputcaps)?
What experience you have with the bass sound in conjunction to the input and output caps?

regards
Henry

[PinkFloyd]

Why is the bass in bad case without high-quality-audio Input-caps in the signalpath??

Hi Henry,

It could be that you've got DC present at your source output in which case that will be entering the amp when you remove the 10uF input caps, have you checked for DC at your source outputs?

Personally, I find the bass response a lot better with the input caps removed as have quite a lot of other people. You are fitting the jumper across the pads right?

[versil]

Hi PinkFloyd,

I was also afraid that DC entered the amp and did the measurement again with no result, still no DC at the CD-output-RCA-sockets. To be very sure I also measured the DC value at the
phono-socket of the V2. Disconnected the HD 600 mini-clips and did the measurement between the slim and the thick pin of each clip..also no DC. Every measurement < 1 mV.

I think I have to agree with you, the bass response seems to be a matter of taste or habit. The assumed punchy, powerful,
head-shaking bass maybe a blurred, resonant or contourless signal. Funny and imposing but unreal for me now.

The jumper were installed correct and I tested it additional with my multitester.

Before a few minutes I had a further workshop with myself :-) witch confirmed my resolution....I kick the noble Cs out. As well
as the hights have a great profit in SQ. There is no denying that the replacement of the stock electrolytics is very huge!! But without any input cap it is a epiphanies.

Anecdote along the way: You ever heard the song "stimela" performed by hugh masekela? In the last third of this live recorded song the male chorus or bandmembers (four singer, left and right to masekela) will break into song (join?) and directly before any tone leave there mouth there is a short noise (only left chanel).
In the past I beliefed the singer bend his head to the micro and his necklace touched shortly the micro. Today I am very shure to know what it was..better I have heard it.....it was these gentle smackly noise you can hear if mostly people open her closed mouth. It is difficult for me to explain it in English...it does not greatly matter. I am astonished an happy about this enormous improvement of Sounddetails.

What do you (or everbody) mean...

- now cut of the output-Cs and jump over?
- any experience in SQ variation without output-Cs?
- no DC at the input than no DC at the output?

Habe a nice weekend,
regards
Henry

[PinkFloyd]

- now cut of the output-Cs and jump over?

I wouldn't recommend removing the output caps, they are there to stop any DC entering your headphones. Even if there's minimal DC at the outputs and you remove the output caps, should a fault occur at any time and large voltages enter your headphones then they will be destroyed so definitely prudent to keep the output caps in place.... they're a belt and braces safety measure.

- any experience in SQ variation without output-Cs?-

Obviously marginally better without them "if" the DC offset at the output is <20mV (less than 20mV with zero being optimal) but, again, in the X-CAN I'd rather have the caps there in series with the outputs just incase anything goes pear shaped. That's what I recommend anyway.... what I do with my own personal X-CAN amps may be a different thing

no DC at the input than no DC at the output?

No, doesn't work that way there can be zero DC at the input but 20 or more VOLTS! at the output under a fault condition.... which is why the output caps are there....... belt and braces protection. Feel free to live life on the edge and remove them but if a fault does occur and your headphones are fried you were warned