And we have lift off!! My Wolverine is finally up and running, some pics of completed build attached.
I joined this thread way back in post #399, where I queried whether, given the lack of any 'how does it sound' type reviews around at that time, I would see any benefit in building the Wolverine amp, over and above my existing My_Ref Fremen Edition Gainclone-based amp, built with 'best' components all round and which I thought (to me!) sounded excellent.
@fireanimal's very encouraging response indicating 'I would not be disappointed' gave me the confidence to go ahead, and now I thought it only be right to post my initial impressions in the hope this may help anyone else who's currently 'sitting on the fence'. As has been said before, any personal review has no real relevance to anyone else, given the myriad of different potential configuration, component, layout, etc. choices each DIY'er might make. So this is NOT a review, it's just my initial personal thoughts with my setup and system .....
System: Macbook Air running Audirvarna 6.5, playing FLAC files into RME ADI-2 DAC FS, Wolverine amp, IPL Acoustics M1tlm transmission line speakers. (Note: sadly, Ivan at IPL retired his business about 18 months ago, such a shame as his speaker kits were excellent).
Anyway - am I disappointed? ABSOLUTELY NO WAY, JOSE!!!
Compared to my My_Ref the overall sound has now 'opened up', with all frequencies having more clarity; bass end is much tighter and just has more drive and purpose to it, highs are crisp and clear, and everything else in between is just as good. As a bonus, it's now allowing the M1tlm's to shine and show what they can really do! Only listened for about an hour so far (Pink Floyd, yeh!), but it's immediately evident what an outstanding amp this really is - many, many thanks to the Wolverine development team for allowing us mere mortals to enjoy such a wonderful amplifier, and thanks also to those that have pointed me in the right direction along the way! Yes, I'm impressed!
Don't get me wrong - for what it is the My_Ref Fremen (LM3886 chip-amp based) is a terrific little amplifier, but it's very, very clear that there is totally no comparison possible with the Wolverine, which is simply a giant leap in comparison!!
I do have a very, very slight hum on both channels which seems to be related to input cable (Mogami microphone cable) - disconnect from input on IPS and it's dead quiet; insert even a short connection (not connected to RCA socket) and hum returns ..... it has me stumped, obviously acting as a good aerial, tried all the usual tricks (cap from RCA 0v to chassis, earthed screens at RCA end, linked screens together, run separate 0v return directly to star ground, turned transformer different directions, moved cables all over the place, and so on) but nothing seems to resolve it. Fortunately, it's so slight that it's only audible if I place my ear almost right against the speaker, so for normal listening it's not a problem.
So, in summary I'd like (with his permission!) to echo @fireanimal's comment that if you decide to go ahead and build this amp 'you will not be disappointed'!
Now, I'm off enjoy some more wonderful sounding music, hope you can all do the same ..... thanks to all,
Richard
I joined this thread way back in post #399, where I queried whether, given the lack of any 'how does it sound' type reviews around at that time, I would see any benefit in building the Wolverine amp, over and above my existing My_Ref Fremen Edition Gainclone-based amp, built with 'best' components all round and which I thought (to me!) sounded excellent.
@fireanimal's very encouraging response indicating 'I would not be disappointed' gave me the confidence to go ahead, and now I thought it only be right to post my initial impressions in the hope this may help anyone else who's currently 'sitting on the fence'. As has been said before, any personal review has no real relevance to anyone else, given the myriad of different potential configuration, component, layout, etc. choices each DIY'er might make. So this is NOT a review, it's just my initial personal thoughts with my setup and system .....
System: Macbook Air running Audirvarna 6.5, playing FLAC files into RME ADI-2 DAC FS, Wolverine amp, IPL Acoustics M1tlm transmission line speakers. (Note: sadly, Ivan at IPL retired his business about 18 months ago, such a shame as his speaker kits were excellent).
Anyway - am I disappointed? ABSOLUTELY NO WAY, JOSE!!!
Compared to my My_Ref the overall sound has now 'opened up', with all frequencies having more clarity; bass end is much tighter and just has more drive and purpose to it, highs are crisp and clear, and everything else in between is just as good. As a bonus, it's now allowing the M1tlm's to shine and show what they can really do! Only listened for about an hour so far (Pink Floyd, yeh!), but it's immediately evident what an outstanding amp this really is - many, many thanks to the Wolverine development team for allowing us mere mortals to enjoy such a wonderful amplifier, and thanks also to those that have pointed me in the right direction along the way! Yes, I'm impressed!
Don't get me wrong - for what it is the My_Ref Fremen (LM3886 chip-amp based) is a terrific little amplifier, but it's very, very clear that there is totally no comparison possible with the Wolverine, which is simply a giant leap in comparison!!
I do have a very, very slight hum on both channels which seems to be related to input cable (Mogami microphone cable) - disconnect from input on IPS and it's dead quiet; insert even a short connection (not connected to RCA socket) and hum returns ..... it has me stumped, obviously acting as a good aerial, tried all the usual tricks (cap from RCA 0v to chassis, earthed screens at RCA end, linked screens together, run separate 0v return directly to star ground, turned transformer different directions, moved cables all over the place, and so on) but nothing seems to resolve it. Fortunately, it's so slight that it's only audible if I place my ear almost right against the speaker, so for normal listening it's not a problem.
So, in summary I'd like (with his permission!) to echo @fireanimal's comment that if you decide to go ahead and build this amp 'you will not be disappointed'!
Now, I'm off enjoy some more wonderful sounding music, hope you can all do the same ..... thanks to all,
Richard
Attachments
Good to hear it is better than Myref. I have a feeling this amp is going to be what I am looking for in the audio reproduction domain. So your feedback is very encouraging.
And we have lift off!! My Wolverine is finally up and running, some pics of completed build attached.
I joined this thread way back in post #399, where I queried whether, given the lack of any 'how does it sound' type reviews around at that time, I would see any benefit in building the Wolverine amp, over and above my existing My_Ref Fremen Edition Gainclone-based amp, built with 'best' components all round and which I thought (to me!) sounded excellent.
@fireanimal's very encouraging response indicating 'I would not be disappointed' gave me the confidence to go ahead, and now I thought it only be right to post my initial impressions in the hope this may help anyone else who's currently 'sitting on the fence'. As has been said before, any personal review has no real relevance to anyone else, given the myriad of different potential configuration, component, layout, etc. choices each DIY'er might make. So this is NOT a review, it's just my initial personal thoughts with my setup and system .....
System: Macbook Air running Audirvarna 6.5, playing FLAC files into RME ADI-2 DAC FS, Wolverine amp, IPL Acoustics M1tlm transmission line speakers. (Note: sadly, Ivan at IPL retired his business about 18 months ago, such a shame as his speaker kits were excellent).
Anyway - am I disappointed? ABSOLUTELY NO WAY, JOSE!!!
Compared to my My_Ref the overall sound has now 'opened up', with all frequencies having more clarity; bass end is much tighter and just has more drive and purpose to it, highs are crisp and clear, and everything else in between is just as good. As a bonus, it's now allowing the M1tlm's to shine and show what they can really do! Only listened for about an hour so far (Pink Floyd, yeh!), but it's immediately evident what an outstanding amp this really is - many, many thanks to the Wolverine development team for allowing us mere mortals to enjoy such a wonderful amplifier, and thanks also to those that have pointed me in the right direction along the way! Yes, I'm impressed!
Don't get me wrong - for what it is the My_Ref Fremen (LM3886 chip-amp based) is a terrific little amplifier, but it's very, very clear that there is totally no comparison possible with the Wolverine, which is simply a giant leap in comparison!!
I do have a very, very slight hum on both channels which seems to be related to input cable (Mogami microphone cable) - disconnect from input on IPS and it's dead quiet; insert even a short connection (not connected to RCA socket) and hum returns ..... it has me stumped, obviously acting as a good aerial, tried all the usual tricks (cap from RCA 0v to chassis, earthed screens at RCA end, linked screens together, run separate 0v return directly to star ground, turned transformer different directions, moved cables all over the place, and so on) but nothing seems to resolve it. Fortunately, it's so slight that it's only audible if I place my ear almost right against the speaker, so for normal listening it's not a problem.
So, in summary I'd like (with his permission!) to echo @fireanimal's comment that if you decide to go ahead and build this amp 'you will not be disappointed'!
Now, I'm off enjoy some more wonderful sounding music, hope you can all do the same ..... thanks to all,
Richard
Hi Richard, an excellent looking build. With the front power power switch what's that wired to?
Thank you!
Soft start module has provision for an on/off switch input, so that's where it goes to (follow white ribbon cable ...), natural advantage of this is that no need for a mains rated switch on front panel as it's only low voltage. Module also has provision for on/off LED, so I've connected that as well - you can just about see the small red LED (2mm diameter) in my photo of front panel, located above the switch.
Hi @voxxonline,
Yes, I think you'll certainly notice the difference compared to the My_Ref. I was expecting (hoping?) the Wolverine would indeed be better, but I'm surprised by how much of a difference there is! Hopefully your experience will be positive as well.
Got it from eBay (https://www.ebay.co.uk/itm/273826988370) .... regards output devices, running at ~50 volts rails I went for NJW0281/NJW0302.
Note that there are different versions for 230V and for 110V. I also used this device, but sometimes it refuses to switch off.
I also had problems that the mounted transformer is too weak for the big relais and hums after switching the relais. In my case a 1,5W Transformer was mounted, I changed it to a 2,8W and now it's fine.
I have to investigate what can be done to make it switch off more reliable..
The relais is labelled Tengfei T-90 12VDC-TF-A. When I search google for this part I find several datasheets of similar looking relais with identical specs. They state a Coil wattage of 0.9VA (DC) and 2 VA (AC). Cool resistance is not explicitly stated.
There are two possibilities: the transformer delivered with this circuit is way weaker than its print states or both relais are engaged after soft start, one for mains and one to bridge the NTCs.
When the circuit is in "standby" the original 1,5W transformers didn't hum. After the second click of the relais it started humming loudly. That's why I think both relais are engaged after the last step of soft start.
I have to remark that I bought similar soft start devices over the last years and every time they arrived with a different transformer and other relais. The older versions did not hum, maybe their transformers where better or the other relais did not need as much power to engage.
I think it may be a problem with the circuit that is receiving the signal from the front panel switch and has to switch the relais. It accepts both momentary and latching switches and should "learn" which one is installed. I think something might be wrong with this routine or maybe I have wired my front panel switches in a wrong way.
I think it may be a problem with the circuit that is receiving the signal from the front panel switch and has to switch the relais. It accepts both momentary and latching switches and should "learn" which one is installed. I think something might be wrong with this routine or maybe I have wired my front panel switches in a wrong way.
Makes sense. I would think the second relay wouldn't close until after a time delay, but not sure how this board is wired. Are the NTC's room temp or just slightly higher or are they hot?
Makes sense. I would think the second relay wouldn't close until after a time delay, but not sure how this board is wired. Are the NTC's room temp or just slightly higher or are they hot?
Hi Richard,And we have lift off!! My Wolverine is finally up and running, some pics of completed build attached.
I joined this thread way back in post #399, where I queried whether, given the lack of any 'how does it sound' type reviews around at that time, I would see any benefit in building the Wolverine amp, over and above my existing My_Ref Fremen Edition Gainclone-based amp, built with 'best' components all round and which I thought (to me!) sounded excellent.
@fireanimal's very encouraging response indicating 'I would not be disappointed' gave me the confidence to go ahead, and now I thought it only be right to post my initial impressions in the hope this may help anyone else who's currently 'sitting on the fence'. As has been said before, any personal review has no real relevance to anyone else, given the myriad of different potential configuration, component, layout, etc. choices each DIY'er might make. So this is NOT a review, it's just my initial personal thoughts with my setup and system .....
System: Macbook Air running Audirvarna 6.5, playing FLAC files into RME ADI-2 DAC FS, Wolverine amp, IPL Acoustics M1tlm transmission line speakers. (Note: sadly, Ivan at IPL retired his business about 18 months ago, such a shame as his speaker kits were excellent).
Anyway - am I disappointed? ABSOLUTELY NO WAY, JOSE!!!
Compared to my My_Ref the overall sound has now 'opened up', with all frequencies having more clarity; bass end is much tighter and just has more drive and purpose to it, highs are crisp and clear, and everything else in between is just as good. As a bonus, it's now allowing the M1tlm's to shine and show what they can really do! Only listened for about an hour so far (Pink Floyd, yeh!), but it's immediately evident what an outstanding amp this really is - many, many thanks to the Wolverine development team for allowing us mere mortals to enjoy such a wonderful amplifier, and thanks also to those that have pointed me in the right direction along the way! Yes, I'm impressed!
Don't get me wrong - for what it is the My_Ref Fremen (LM3886 chip-amp based) is a terrific little amplifier, but it's very, very clear that there is totally no comparison possible with the Wolverine, which is simply a giant leap in comparison!!
I do have a very, very slight hum on both channels which seems to be related to input cable (Mogami microphone cable) - disconnect from input on IPS and it's dead quiet; insert even a short connection (not connected to RCA socket) and hum returns ..... it has me stumped, obviously acting as a good aerial, tried all the usual tricks (cap from RCA 0v to chassis, earthed screens at RCA end, linked screens together, run separate 0v return directly to star ground, turned transformer different directions, moved cables all over the place, and so on) but nothing seems to resolve it. Fortunately, it's so slight that it's only audible if I place my ear almost right against the speaker, so for normal listening it's not a problem.
So, in summary I'd like (with his permission!) to echo @fireanimal's comment that if you decide to go ahead and build this amp 'you will not be disappointed'!
Now, I'm off enjoy some more wonderful sounding music, hope you can all do the same ..... thanks to all,
Richard
I'm so pleased that you are happy with your wolverine build. Thank you for taking the time to give us your personal thought's regarding how it sound etc...
I would like to offer a few suggestions that may help to silence the small amount of hum that you are hearing.
1. The first thing you can try is to isolated and test each amplifier module first. To do this disconnect the DC rails, speaker outputs and input signal wire from one amplifier module. Now test the second by shorting the input directly at the ips input terminal with a small piece of wire. Next disconnect the speaker outputs and then measure the A/C voltage between the output terminal and the speaker return. Ideally it should be as low as possible.
I will do some actual testing with my signal generator and speaker and get back to you later with some values. Speaker sensitivity will also have an effect on the numbers.
Once you test each amplifier module like this you will have your minimum baseline. Then you can re connect all your wiring and retest. This time shorting the input at the RCA connector on the outside of your chassis. If you notice any increase in AC voltage this could indicate a issue with your wiring.
As far your wiring layout goes, it looks pretty good. If I could make a few suggestions to try they would be.
2. Move the DC Wiring to the bottom corner of your chassis as shown in the attached image. This will reduce your loop area.
3. Try and bring your dc input terminals together and meet at the 0v psu ground. To do this you will need to use some type of cylindrical stand off to space off the ring terminal allowing you to rotate the lead over the top of the fuse holders.
See attached image for the general idea.
4. As your chassis does not have any vertical clearance above the speaker out and speaker return terminals I would bring them out at 90° to the board and then twist them together and route them to your speaker protection and speaker binding posts. Currently you have them close the the negative rail wire connecting to the pcb. This could inject half wave receiving noise into you output wiring. See attached image.
5. Is the signal wire that you are using twisted? Is it shielded? It doesn't look like it. You may want to try some twisted and shielded signal wire like a microphone cable. See Attached images.
Hope that helps.
Attachments
Hi Studley,
I purchased it online from Oritech in Australia P/N: 701-182. There is a near identical version made by Aven (P/N: 17560). The Aven version is available from several suppliers such as Digikey and Mouser Electronics.
Cheers
Paul
Hi Studley,
Sorry I just realized you were referring to the PCB holder not the solder holder. Ignore the previous post. There are several brands making these and I believe the one I have is from Elcontrol (Model PCSS/1). Ideal-Tek also make a similar product. This one actually belongs to my work as they are quite expensive. The lid comes with an antistatic foam insert which allows you to clamp all the components to the PCB so that you can flip it upside down and solder away.
Cheers
Paul
Hi Stuart,
Many thanks for your comments, suggestions and advice! I'll try some of your tips when I can, not sure when I'll get round to it because the amp's now fitted in situ and in use - a bit 'shoe-horned' into place so not so easy to remove, but I will try, honest!
Meanwhile, to answer some of your points:
1. The first thing you can try is to isolated and test each amplifier module first. To do this disconnect the DC rails, speaker outputs and input signal wire from one amplifier module. Now test the second by shorting the input directly at the ips input terminal with a small piece of wire. Next disconnect the speaker outputs and then measure the A/C voltage between the output terminal and the speaker return. Ideally it should be as low as possible.
I will do some actual testing with my signal generator and speaker and get back to you later with some values. Speaker sensitivity will also have an effect on the numbers.
Once you test each amplifier module like this you will have your minimum baseline. Then you can re connect all your wiring and retest. This time shorting the input at the RCA connector on the outside of your chassis. If you notice any increase in AC voltage this could indicate a issue with your wiring.
- I must admit I've not measured AC (DC was essentially 0), but disconnecting at input terminal leaves that channel dead quiet, zero hum, Shorted or not, still zero hum so simply removing the cable removes the hum. Leaving the input connected introduces hum and then shorting RCA's together outside the chassis (using a quality lead) makes no difference at all to this. So all the evidence seems to point towards the cable from RCA to input itself picking up interference.
2. Move the DC Wiring to the bottom corner of your chassis as shown in the attached image. This will reduce your loop area.
- I have tried my best to comply with Bonzai & others' excellent suggestions for reducing loop areas, etc., hence I've tried to keep potential loops low and separated. The speaker output for channel 1 (towards left on my pics) runs across the centre of the front panel, before dropping down to run at low level along RH edge of base plate underneath channel 2 - exactly where you propose for me to run the DC wires! Hence that's why I thought best to run the DC where it is, so as not to conflict with speaker wires. Is that not a good plan? If DC wires run alongside (parallel) to speaker wires wouldn't that make matters worse?
3. Try and bring your dc input terminals together and meet at the 0v psu ground. To do this you will need to use some type of cylindrical stand off to space off the ring terminal allowing you to rotate the lead over the top of the fuse holders.
See attached image for the general idea.
- Understood!
4. As your chassis does not have any vertical clearance above the speaker out and speaker return terminals I would bring them out at 90° to the board and then twist them together and route them to your speaker protection and speaker binding posts. Currently you have them close the the negative rail wire connecting to the pcb. This could inject half wave receiving noise into you output wiring. See attached image.
- Understood!
5. Is the signal wire that you are using twisted? Is it shielded? It doesn't look like it. You may want to try some twisted and shielded signal wire like a microphone cable. See Attached images.
- Signal wire is Van Damme Reduced OD Console Cable, which is foil screened (with additional screen wire) twisted pair and which I thought should do the job! Maybe not - would a better/different cable make a difference do you think? 0v's are connected together at RCA's and as I mentioned in my earlier post, I've tried this with leaving screen disconnected (both ends), linking both screens together, connecting screen(s) directly to chassis at RCA end, connecting screen(s) via small cap to chassis at RCA end, connecting screen(s) directly to star ground point, connecting 0v input directly to star ground point - nothing makes any difference except removing the cable from input!
As always, your guidance is greatly appreciated!
Many thanks,
Richard
Many thanks for your comments, suggestions and advice! I'll try some of your tips when I can, not sure when I'll get round to it because the amp's now fitted in situ and in use - a bit 'shoe-horned' into place so not so easy to remove, but I will try, honest!
Meanwhile, to answer some of your points:
1. The first thing you can try is to isolated and test each amplifier module first. To do this disconnect the DC rails, speaker outputs and input signal wire from one amplifier module. Now test the second by shorting the input directly at the ips input terminal with a small piece of wire. Next disconnect the speaker outputs and then measure the A/C voltage between the output terminal and the speaker return. Ideally it should be as low as possible.
I will do some actual testing with my signal generator and speaker and get back to you later with some values. Speaker sensitivity will also have an effect on the numbers.
Once you test each amplifier module like this you will have your minimum baseline. Then you can re connect all your wiring and retest. This time shorting the input at the RCA connector on the outside of your chassis. If you notice any increase in AC voltage this could indicate a issue with your wiring.
- I must admit I've not measured AC (DC was essentially 0), but disconnecting at input terminal leaves that channel dead quiet, zero hum, Shorted or not, still zero hum so simply removing the cable removes the hum. Leaving the input connected introduces hum and then shorting RCA's together outside the chassis (using a quality lead) makes no difference at all to this. So all the evidence seems to point towards the cable from RCA to input itself picking up interference.
2. Move the DC Wiring to the bottom corner of your chassis as shown in the attached image. This will reduce your loop area.
- I have tried my best to comply with Bonzai & others' excellent suggestions for reducing loop areas, etc., hence I've tried to keep potential loops low and separated. The speaker output for channel 1 (towards left on my pics) runs across the centre of the front panel, before dropping down to run at low level along RH edge of base plate underneath channel 2 - exactly where you propose for me to run the DC wires! Hence that's why I thought best to run the DC where it is, so as not to conflict with speaker wires. Is that not a good plan? If DC wires run alongside (parallel) to speaker wires wouldn't that make matters worse?
3. Try and bring your dc input terminals together and meet at the 0v psu ground. To do this you will need to use some type of cylindrical stand off to space off the ring terminal allowing you to rotate the lead over the top of the fuse holders.
See attached image for the general idea.
- Understood!
4. As your chassis does not have any vertical clearance above the speaker out and speaker return terminals I would bring them out at 90° to the board and then twist them together and route them to your speaker protection and speaker binding posts. Currently you have them close the the negative rail wire connecting to the pcb. This could inject half wave receiving noise into you output wiring. See attached image.
- Understood!
5. Is the signal wire that you are using twisted? Is it shielded? It doesn't look like it. You may want to try some twisted and shielded signal wire like a microphone cable. See Attached images.
- Signal wire is Van Damme Reduced OD Console Cable, which is foil screened (with additional screen wire) twisted pair and which I thought should do the job! Maybe not - would a better/different cable make a difference do you think? 0v's are connected together at RCA's and as I mentioned in my earlier post, I've tried this with leaving screen disconnected (both ends), linking both screens together, connecting screen(s) directly to chassis at RCA end, connecting screen(s) via small cap to chassis at RCA end, connecting screen(s) directly to star ground point, connecting 0v input directly to star ground point - nothing makes any difference except removing the cable from input!
As always, your guidance is greatly appreciated!
Many thanks,
Richard
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Thanks. I asked because I’m currently looking to buy a pcb holder that you can rotate for soldering. Yours sounds as though it will be beyond my budget, so I’ll probably settle for one of those relatively inexpensive plastic ones.