I have Win 7 x64 and next issues with GOG's GK1:
1) The sound of voices. It's unstable. It's all time doing slow/fast pronouncing of some part of words. If you will try again the pronouncing will be ok for that world but will be ugly with another. Maybe it can be fixed it dosbox config files?
2) Music level. It's always play's on a maximum, even if bar will be down. Each time I need to go to options and click at least on same level to make music not screaming loud.
Maybe it can be fixed in game's config files?
3) Day2, at Gedde house. All voice are playing after animations scenes (3-4 sec after). Bug how can be fixed?
Many thanks in advance.

Hope this might be a bit like the problem I encountered on my Vista x64. The voices seemed to glitch and stutter. For me it seems to have been a problem with the amount of cycles. Initially I just edited dosboxGK.conf (use notepad or something), find the line saying cycles=max and edit it. I tried doing cycles=20000
Still not sure about Dosbox and proper cycle setup. Seems to be system dependent what a certain cycle setup means. But try it somewhere around there. This seems to have abolished the glitching, slight clicking can still occasionally be heard when new speech is started. Further tweaking might work for this. Still far preferable to the glitching which could cause you to lose important pieces of the dialog

The Sierra SCI games should usually be set at no higher than around 10000. Any higher and you can start to run into timer bugs. As far as the dosboxGK.conf, it is an outdated config file (for 0.72) that can cause issues. A minimal config file with just your custom settings will prevent DOSBox from using an earlier versions defaults. The best thing that you can do for better sound is to upgrade your DOSBox to 0.74 and use the following for the config:
[sdl]
output= overlay
fullresolution= 0x0
windowresolution= 800x600
fullscreen= false
autolock=false
[render]
scaler= normal3x
[cpu]
core= normal
cycles= 10000
[autoexec]
(copy and paste the [autoexec] of your existing file here)
You can change some of the setting to suit you, like "fullscreen="

I suggest not using "Output=overlay" but rather "output=ddraw" which results in much smoother gameplay for me.
Also, the problem with voices and animation not in sync will happen a couple of times in GK and is, as far as I can tell, a problem with AUDBLAST.DRV and happens everytime there is background noise.
Collector is right, though, most problems vanish as soon as you keep your icles at (or under) 10000.

A matter of personal tastes and individual machines.
That is why I said that you should upgrade DOSBox to 0.74. Sierra's flaky SB driver does better under 0.74 than any earlier version of DOSBox.

A matter of individual machines for sure. It's just a suggestion to try. The display doesn't change it's just smoother. I always had troubles with fade outs and similar effect with overlay.
And, thank you, I really wasn't aware that there is a new version of DOSBox. I'll download it immediately.

This may be a stupid question but; if I download the new DOSbox does it automatically run all my GOG games or do I have to manually start them?
For example I´m currently playing World of Xeen (Might & Magic 4-5) will DOSbox 0.74 be upgraded there to?

I haven't tried installing a gog game without installing dosbox. In this case anyway dosbox is in the DOSBOX folder under the game.
I just installed dosbox 0.74, then copied the dosbox folder from program files and pasted it into the game's folder beside it's already existing dosbox folder, then renamed the two so the 0.75 install is now just called Dosbox. Works fine for me

I did as you said but instead of keeping the old DOSBOX folder I deleted it and kept only the new one, with 0.74 in it. The game works fine and my old shortcut works.
Thanks!

No problem. Not sure how it would work if you used a centralized Dosbox install (e.g. decide to not install dosbox with the game I'm guessing it might ask for where dosbox is located)
Reason I kept the old version was to be certain if there were compatibility issues I could roll back

How do I do that and what am I supposed to change in the conf file?
Not good with computers so please make it easy;)

Hmm. I've did it and game is almost unplayable now.
First of all it not helpsat all with pause between text/animation and voice after 4sec at Geddi's Mansion and Napoleon's Bar.
The second - game is slow as hell. When I'm trying lookout place and using binoculars it's like 1fps per minute. Extremely slow and hard.
Third is up to animation. It's really slow and really bad now (even on max "Speed"). Like I'm trying to run GK1 at ZX Spectrum.
Any recomendation, what can be done?
Many thanks in advance.

You can increase cycles, but once you get much above 10000 you can start to get the timer bugs popping up. Try playing around with the "output=" in the conf file.
Move or rename dosboxGK.conf in the game's folder. Then just paste what I posted above into Notepad and then copy and paste from the [autoexec] from your current conf file. Save the new file as "dosboxGK.conf " in the GK folder.
Edit: If someone posts the content of their [autoexec] I can make a small utility to make it very easy to make changes to the conf file.

Ehh. No matter anymore.
Finished with 341 from 342. Was missed somehing. Darn.
It was my first time. I'm enjoyed the game.
Were tried all options with config what was able to change, but nothing.
So played time-to-time as slow-freak-mo when cycles 10k and time to time with cycles=auto in normal "cartoon" mode.
But still this anoying #$%@ with text first, than voice - so each scene like 2x more longer. Were affected with this bug: Napoleon's bar, Gedde's Mansion, Wolfgang's Bedroom, couple of other scenes, and most tragic it was at all Mummies scenes and at final internal circle in New Orlean. Final sene is epic sucks due this bug, it's like heroes saying "Now you will DIE!!!!" and waiting another 4-5 seconds for next dialogue line. Real crap.
Ok, need to go forward with it. Next stop station is GK2.