I've just bought a Focusrite Scarlett Solo, and testing it with my existing installation of Sonar. I've fully uninstalled ASIO4All (that I was using previously), but haven't yet tried a full Windows / Sonar reinstall.
 
Some VSTs have a rhythmic clicking on playback. Changing the buffer sizes only seems to change the speed of the clicking (and even at 1024 samples, I still hear clicks).
 
I can play the same VSTs outside of Cakewalk using SAVIHost (standalone VST host) and they play fine without any problems.
There are also a number of VSTs that do appear to play OK in Cakewalk.
 
It appears to be my older VSTs that have issues, so I'm wondering if it's a 32bit/64bit issue? I did install the x64 version of Sonar (it's a 64bit PC) - I haven't seen any issues previously when using ASIO4All (and a cheap Beranger interface).
However, the rgc Audio Square 1 is listed as '32bit' in description, but works OK - not sure why? (Full list of VSTs tested below).
I also tested live audio FX using a guitar and TH2 Producer - that also worked without issue.
 
Focusrite driver installed is 4.15.0.172
Sonar X3 version is X3e build 352 x64
PC Specs are  Core i7 4790S CPU @ 3.20 GHz 16GB RAM 64bit Windows 10 Pro
 
Does anyone have any ideas / suggestions / thoughts on this? I probably will do a full Windows reload in the next couple of weeks, but I'm not sure this will help in this instance?
 
Thanks very much,
Paul
 
 
All of the following VSTs appear to working OK:
Addictive Drums 2
Dimension Pro
Rapture
Session Drummer 3
sfz
SI Bass / Drums / Keys / Strings
rgc Audio Square 1  (Not sure why, as this is listed as 32 bit???)
Strum Acoustic
z3ta+
True Piano Cakewalk
TTS1
PSYN II
Roland GrooveSynth
 
TH2 Producer (Guitar FX for live audio input) also working fine
 
All of these plugins produce regular clicking when notes are played:
Cakewalk Sound Centre
DropZone
Korg WaveStation
Native Instruments B4
SampleTank

Does the problem persist when using drivers other than the ones from Focusrite? Give WASAPI a try.
 
Contact Focusrite for support if it just happens with their driver.
 
I would only reinstall as a last resort.
 

Yep, I've got a call logged with Focusrite as well....
However, the Focusrite ASIO drivers work fine with a standalone VST host, so I think it's a Sonar issue
I tried WASAPI drivers, but I couldn't get any sound out - however, I wasn't getting any signal from the audio track (despite having signal on the midi track, and that output going to the audio track). I'll try again a bit later......
 
Thanks for your suggestions...

Managed to get both WASAPI and WDM drivers working with the Focsurite - but only at latency of 20ms (and lower and it started to generate clicks - not as badly as ASIO, but still unusable).
Tomorrow I may try and re-install ASIO4All - but to be honest one of the main reasons for buying the Focusrite was to get something with 'proper' drivers...
I may also try putting Sonar onto this laptop and try the Focusrite on there to see if it behaves the same.
 
The fact that it's only certain VSTs (and mostly older, probably 32bit ones) - I still think that could be a factor in this issue??

You should be getting better performance with ASIO than that.  A few things to try /look at:
 
- Make sure you have the proper generation (1st or 2nd) drivers for your Solo.
 
- Connect the Solo only to a USB2 port (not USB3).  Or, try a different USB2 port.
 
- Did you do a reset & rescan of VSTs?

Thanks Jon
Definitely latest driver for 2nd gen device
I did see some other articles mentioning USB2/3 - unfortunately I think my PC is USB3 only - not sure how I deal with this if it is a USB3 problem - maybe a USB2 hub? (although I wouldn't normally want to put an audio device through a hub...) 
Thanks for the suggestion on reset/rescan VST - I hadn't come across that setting before, so I'll try that next...
Cheers 

A USB3 port with Intel controller/driver "might" work.  A look at the device manager will tell you if you have any.
 
An added hub won't make a difference if it's connected to a USB3 port.
 
If this is a desktop, there's another, easier solution. You can buy a relatively cheap USB2 PCIe add-on card like this one:
 
https://www.amazon.com/Syba-Expres-5-port-Host-Controller/dp/B0026I4DZ2

You could try a clean boot, on the off chance you have something in your startup that's causing a conflict with Sonar and the Focusrite driver.
 
How to perform a clean boot in Windows
https://support.microsoft.com/en-us/kb/929135
 
There also this, in case you missed it...
 
https://www.cakewalk.com/Support/Knowledge-Base/2007013376/Windows-Optimization-Guide
 

A long-shot, but worth a try...
 
Under Pref/Audio/Driver settings:  Disable 64-bit Double Precision Engine (Has been known to cause problems with some plugins).

Thanks all
I found articles last night suggesting some DELL's have options in the BIOS to reduce USB3 down to USB2 for compatibility, but it appears my BIOS doesn't!
I've been looking at USB Device Tree Viewer - according to that the USB ports I'm using are marked as 'H' (which is USB2) - there are some ports marked as 'S' but they don't connect when I use any of the 6 ports I have available. Not sure if the software is reading my device correctly or not?
The driver for the controller is shown as Intel(R) USB 3.0 eXtensible Host Controller - 1.0 (Microsoft).
(Unfortunately I don't have any PCI slots - it's a DELL HPS 2720 All-in-one PC - basically it's a laptop motherboard inside the case)
 
Tried the VST reset and rescan - no change
Tried reinstalling ASIO4All - the only way I can get this to sound with the Solo is by enabling Hardware buffers (which gives appalling latency) - but this did have one interesting outcome - the Solo output still 'clicks' when using ASIA4All in Cakewalk (on the affected VSTs), but doesn't click when using the standalone VST host.
 
So the problem does not appear to be limited to the Focusrite drivers - it does appear to be an incompatibility between the Focusrite Hardware, Sonar, and specific (possibly 32bit?) VSTs.
I'm not sure when I'll get time to run up Sonar on a laptop - but I'll try that next (as I'm fairly sure the laptop is only USB2). I'll also try some of the performance settings on the PC to see if they help (but I'm trying to play single notes on one VST with no other audio / midi / effects - on an i7 PC with 16Gb RAM - I highly doubt it's performance related!)
 
Thanks for all your help and suggestions, I will keep this thread updated with progress...