You can alter the sound of an amplifier considerably by a careful choice/change of components be it in the direct signal path, feedback path, etc or more significantly, in the - perhaps a bit beyond the real novice beginner but certainly well within the grasp of anyone assembling their own devices.
For example, a change from say a metal film resistor from a cheap china house/discount price component store, etc to perhaps a reasonable PRP resistor will bring quite a change - same thing with power supply capacitors
So, if you're willing to play around with 'better quality' resistors and caps, you can 'brighten-up' and 'soften' the sound of an amp to quite a large degree.
You'll notice that I've carefully avoided the term 'better quality' as this will be a choice for each of us and largely determined by the associated equipment and the room you're listening with/in.
... my 2 cents
For example, a change from say a metal film resistor from a cheap china house/discount price component store, etc to perhaps a reasonable PRP resistor will bring quite a change - same thing with power supply capacitors
So, if you're willing to play around with 'better quality' resistors and caps, you can 'brighten-up' and 'soften' the sound of an amp to quite a large degree.
You'll notice that I've carefully avoided the term 'better quality' as this will be a choice for each of us and largely determined by the associated equipment and the room you're listening with/in.
... my 2 cents
Hi JH,
May I ask what your A/B setup is? I have built a lot of amps now and tried many of the so called, "better" components but when all is said and done it is almost undetectable. I'm curious which amps you have built in which you built them two ways, one with the "better parts" and the other with common parts and then how you went about doing a blind test to come to the conclusion that the sound was significantly altered.
Thanks, Terry
May I ask what your A/B setup is? I have built a lot of amps now and tried many of the so called, "better" components but when all is said and done it is almost undetectable. I'm curious which amps you have built in which you built them two ways, one with the "better parts" and the other with common parts and then how you went about doing a blind test to come to the conclusion that the sound was significantly altered.
Thanks, Terry
My setup is fairly simple, most home built with a NOS 16/44k cd player setup and the alternative Ayre Acoustic QB-9 usb dac (with jRiver, etc) - preamp is still the switched LDR passive vol control and then there's a selection of amps from an 845 valve amp, F3, F5 and the GB150 - speakers are about to be rebuilt but retaining the modded Coral beta8 FR driver (from 120Hz+ ) and the Lorantz 12" bass - still using the passive Xover while sorting out some electronic or DSP options - room treatments, naturally - ChimeraLabs wiring - Mad Scientist Audio 'toys', amongst the many .... No vinyl/phono anymore.
I tend to resort to headamp (Cavalli) and the AKG k701s, Audeze, etc for the more critical evaluations - still making mistakes and trying to avoid pre-conditioning - my opinion only, as we're each different.
The most 'touchy' amp for me is the First watt F5 - I've done a couple of these and the first was pretty much as per circuit with reasonable components (dale small resistors and Panasonic powers) and with thre Coral speakers the sound was a bit bright and 'in the face' - no real surprised there as the Coral are a bit of a challenge but checked sound with a pair of Flat 8's that are a lot less resonant/peakie.
Last one was a full out effort with good parts everywhere and included such esoteric things like dc traps, secondary snubbers, quiet diodes, split CRC into Cmulti supplies and to match up this used some of the Rhopoint resistors, some IsaBellen's PBHs, reduced feedback and the big Toshiba power Fets (later changed to juma's 2sk2013/j313 cct) - a bit over the top, I admit, but the sound was a completely different, with a quite pronounced softer, more musical tone without loss of any detail or 'speed' (sorry for vague terms) - quite impressive for it's lack of many of those 'audiophile' qualities that are common these days - only lack is the relatively low power rails that loud transients reach a bit.
I bought a Factory F3 from 'the man' and it had a bit of a problem with 'speed' (IMO, rather 'slow' amp but 'nice with it'!) so this also received capacitor upgrades (particularly the electro in the active current source circuitry) and then most of the resistors also got a transplant with much faster, more dynamic behaviour altogether where the current drive really made the corals speaker perform very well.
Limited explanation, sorry, but perhaps it gives a bit of an idea 'where I'm coming from' so-to-speak.
Recently had a bit of time with couple of amps called THRAX, from Romania, I think - very impressive indeed as they didn't seem to have a sound at all, even with really complicated music into a pair of the medium sized Brodman speakers, particularly with piano music and ensemble - 'slumming' with the 'audiophiles'! - way beyond my financials, but added to the 'wish list'!
I tend to resort to headamp (Cavalli) and the AKG k701s, Audeze, etc for the more critical evaluations - still making mistakes and trying to avoid pre-conditioning - my opinion only, as we're each different.
The most 'touchy' amp for me is the First watt F5 - I've done a couple of these and the first was pretty much as per circuit with reasonable components (dale small resistors and Panasonic powers) and with thre Coral speakers the sound was a bit bright and 'in the face' - no real surprised there as the Coral are a bit of a challenge but checked sound with a pair of Flat 8's that are a lot less resonant/peakie.
Last one was a full out effort with good parts everywhere and included such esoteric things like dc traps, secondary snubbers, quiet diodes, split CRC into Cmulti supplies and to match up this used some of the Rhopoint resistors, some IsaBellen's PBHs, reduced feedback and the big Toshiba power Fets (later changed to juma's 2sk2013/j313 cct) - a bit over the top, I admit, but the sound was a completely different, with a quite pronounced softer, more musical tone without loss of any detail or 'speed' (sorry for vague terms) - quite impressive for it's lack of many of those 'audiophile' qualities that are common these days - only lack is the relatively low power rails that loud transients reach a bit.
I bought a Factory F3 from 'the man' and it had a bit of a problem with 'speed' (IMO, rather 'slow' amp but 'nice with it'!) so this also received capacitor upgrades (particularly the electro in the active current source circuitry) and then most of the resistors also got a transplant with much faster, more dynamic behaviour altogether where the current drive really made the corals speaker perform very well.
Limited explanation, sorry, but perhaps it gives a bit of an idea 'where I'm coming from' so-to-speak.
Recently had a bit of time with couple of amps called THRAX, from Romania, I think - very impressive indeed as they didn't seem to have a sound at all, even with really complicated music into a pair of the medium sized Brodman speakers, particularly with piano music and ensemble - 'slumming' with the 'audiophiles'! - way beyond my financials, but added to the 'wish list'!
Hi James,
OK so if I'm reading your explanation correctly, you built two F5's, one with standard parts and one with full blown audiophile parts and sounds like you added some extra circuitry as well. Then you also built two separate F3's as well, or did you just modify the F3? You gave a nice description of your system components but you didn't describe your A/B setup. How are you going about doing your blind testing? Were you able to test the two F5's side by side with identical source and speaker, equalized volume and instant switching? How about the F3's?
Thanks, Terry
OK so if I'm reading your explanation correctly, you built two F5's, one with standard parts and one with full blown audiophile parts and sounds like you added some extra circuitry as well. Then you also built two separate F3's as well, or did you just modify the F3? You gave a nice description of your system components but you didn't describe your A/B setup. How are you going about doing your blind testing? Were you able to test the two F5's side by side with identical source and speaker, equalized volume and instant switching? How about the F3's?
Thanks, Terry
No problems Terry, I've done about couple of basic F5s as I think they're a really useful amps for matching up with all sorts of speaker systems - the better one with the big Toshiba fets got upgraded to the 2013/313 variation of juma's design and that's the last one I built.
I got the GB150 mainly to drive the new 15" bass drivers which is a bit of a waste of that amp's capabilities, I guess, but I wasn't all that confident about using the classD amps up to 150Hz at a 12dB/oct filter slope and I'd heard Greg's gb150 bass performance - was going to try to get one of those 100W Krell clones up and running, but good sense prevailed.
I don't find most of the A/B Blind Testing to be very useful, except to highlight immediate differences - in my opinion, you need a bit of time listening to any particular combination of amp/speakers, especially if you're doing an evaluation, so swapping between amps &/or speakers doesn't seem to work for me, unfortunately. I just end up confused as to what amp is doing what and 'lose the plot' altogether and end up just tired and irritable
However, changing components in the same amp is relatively straight forward to check out the change in sound, probably as I've done so much of it over the years - I caught the 'tweaker habit' a long time ago!
I seem to have developed a fairly good memory for picking differences and working thru the mental check-list of audible characteristics makes the process fairly consistent - that's no problem really, but what sneaks up you is that your musical appreciation inevitably changes as you age and you definitely prefer different characteristics as your expand your musical horizons -
Well, this happens/is happening to me anyway so I am much more critical of the system performance than I was 5 years ago - could also be an age 'thing', getting to be a 'crotchety ol' man' that doesn't tolerate irregularities in system response very well these days.
Curiously, I had both the 'good' F5 (the rather expensive one) and the basic version here awhile ago on the system here for an 'audio night' and the basic amp was quite aggressive in sound when compared to the 'fancy one" but you'd expect that as the system has been optomised to suit that amp.
The F3 amp was upgraded, full stop - I was rather dissatisfied with it's performance despite it's amazing ability to produce an extraordinary sound from the Corals and a couple of the other high efiiciency drivers we tried - I even got a much more linear sound from the *' Lowthers, the ceramic ones, Xed over at the same 150Hz - we had a couple of standard F3 here in Melbourne at the time, as a comparison but I didn't revert back to original components at all.
Anyway, that's just me - looking at your amp build list below your 'signoff', you have indeed built a very wide range of amplifiers indeed from the AlephX to the KSA-50 (huge difference in sound to me) and more modern ones - I haven't found what speakers/room you use so maybe that's why the component differences aren't so apparent with your setup - also maybe I'm talking thru my hat, too!
I hope this is at least entertaining!
I got the GB150 mainly to drive the new 15" bass drivers which is a bit of a waste of that amp's capabilities, I guess, but I wasn't all that confident about using the classD amps up to 150Hz at a 12dB/oct filter slope and I'd heard Greg's gb150 bass performance - was going to try to get one of those 100W Krell clones up and running, but good sense prevailed.
I don't find most of the A/B Blind Testing to be very useful, except to highlight immediate differences - in my opinion, you need a bit of time listening to any particular combination of amp/speakers, especially if you're doing an evaluation, so swapping between amps &/or speakers doesn't seem to work for me, unfortunately. I just end up confused as to what amp is doing what and 'lose the plot' altogether and end up just tired and irritable
However, changing components in the same amp is relatively straight forward to check out the change in sound, probably as I've done so much of it over the years - I caught the 'tweaker habit' a long time ago!
I seem to have developed a fairly good memory for picking differences and working thru the mental check-list of audible characteristics makes the process fairly consistent - that's no problem really, but what sneaks up you is that your musical appreciation inevitably changes as you age and you definitely prefer different characteristics as your expand your musical horizons -
Well, this happens/is happening to me anyway so I am much more critical of the system performance than I was 5 years ago - could also be an age 'thing', getting to be a 'crotchety ol' man' that doesn't tolerate irregularities in system response very well these days.
Curiously, I had both the 'good' F5 (the rather expensive one) and the basic version here awhile ago on the system here for an 'audio night' and the basic amp was quite aggressive in sound when compared to the 'fancy one" but you'd expect that as the system has been optomised to suit that amp.
The F3 amp was upgraded, full stop - I was rather dissatisfied with it's performance despite it's amazing ability to produce an extraordinary sound from the Corals and a couple of the other high efiiciency drivers we tried - I even got a much more linear sound from the *' Lowthers, the ceramic ones, Xed over at the same 150Hz - we had a couple of standard F3 here in Melbourne at the time, as a comparison but I didn't revert back to original components at all.
Anyway, that's just me - looking at your amp build list below your 'signoff', you have indeed built a very wide range of amplifiers indeed from the AlephX to the KSA-50 (huge difference in sound to me) and more modern ones - I haven't found what speakers/room you use so maybe that's why the component differences aren't so apparent with your setup - also maybe I'm talking thru my hat, too!
I hope this is at least entertaining!
I made the same observation on the number of amps he built and asked Terry about his favorite in another thread. I think it was the slewmaster but he might have blown that up so the honey badger has no real competition right now 😉
I'm closely following his posts in the Unique CFA thread because I have a box that would suit that amp design well. As far as the SKA150 goes: The front end drive seems to dictate how well the upper frequencies are represented. When those parts have higher beta, they will sound brighter. Also note the original GB150 boards have a slightly different grounding scheme than the ones you get on Ebay. I don't have the equipment to see distortion that low but some claim there is a sonic difference that I haven't heard.
I'm closely following his posts in the Unique CFA thread because I have a box that would suit that amp design well. As far as the SKA150 goes: The front end drive seems to dictate how well the upper frequencies are represented. When those parts have higher beta, they will sound brighter. Also note the original GB150 boards have a slightly different grounding scheme than the ones you get on Ebay. I don't have the equipment to see distortion that low but some claim there is a sonic difference that I haven't heard.
Hi Dellama,
I'm sorry if I wasn't clear. I have no favorite when it comes to the sound. IMO, all of the better ones are so close to each other that any of them could be someone's favorite amp. The Slewmaster is more a format than an amp per se. It was designed as a base to test and compare different topologies, mainly CFA vs VFA, but it has become way more than that. To date I think we have something like 7 or 8 different IPS and at least 4 different OPS sections. A DIYers dream if you ask me. I'm not sure if I would recommend it to someone who only want to build one amp. It takes up more real estate that most of the other amps because of the 4 boards required. I would definitely recommend the Badger. It has great support, a nice instruction manual and will accept a wide range of parts. I think the chances for success are very good with that amp. The SKA is a little tougher to get right. Some of the input section BJTs are hard to come by and the outputs need to be matched. I built two pair of the SKA. One with all expensive caps and the other without. I would defy you to hear any difference. As for my speakers, I have a pair of JBL 4412, a pair of JBL 4425 and a pair of Event 20/20 nearfields set up in my room. Each of them have their own "color". They were each designed as studio monitors so though they are now called "vintage" the fidelity is excellent. I'm attaching a pic showing the JBL' as they are set up.
Blessings, Terry
I'm sorry if I wasn't clear. I have no favorite when it comes to the sound. IMO, all of the better ones are so close to each other that any of them could be someone's favorite amp. The Slewmaster is more a format than an amp per se. It was designed as a base to test and compare different topologies, mainly CFA vs VFA, but it has become way more than that. To date I think we have something like 7 or 8 different IPS and at least 4 different OPS sections. A DIYers dream if you ask me. I'm not sure if I would recommend it to someone who only want to build one amp. It takes up more real estate that most of the other amps because of the 4 boards required. I would definitely recommend the Badger. It has great support, a nice instruction manual and will accept a wide range of parts. I think the chances for success are very good with that amp. The SKA is a little tougher to get right. Some of the input section BJTs are hard to come by and the outputs need to be matched. I built two pair of the SKA. One with all expensive caps and the other without. I would defy you to hear any difference. As for my speakers, I have a pair of JBL 4412, a pair of JBL 4425 and a pair of Event 20/20 nearfields set up in my room. Each of them have their own "color". They were each designed as studio monitors so though they are now called "vintage" the fidelity is excellent. I'm attaching a pic showing the JBL' as they are set up.
Blessings, Terry
Attachments
I know, the new amp designs have gotten better and cleaner than the sources and loudspeakers. In my case, my sources are the weak link. I have a vintage set of Fisher's ill fated top of the line "Studio Standard" loudspeakers which I deployed three years ago. I found them in original packaging in time warp condition. They have tightly matched drivers and parts. They were serialzed and I've put them up against current B&W's and other multi-K speakers where they rate comfortably in the middle of the pack. I've heard those JBL 4425's and they are pretty good but a bit polite.
I agree. The hardest part in building an amp is choosing the one to build. The comment on Sna was a result of a comparison that was had at my place between my honeybadger and the gb150. At that time we couldn't here a difference. That was at that time though. An early stage in my hifi hobby. Since then many changes have been.had and the system now more easily recognise when a change is made(the systemisbetter these days). Would be interested in a comparison these days.
I find it odd terry that you have not heard many differences between your amps. In the experiments i've done I've found that a good quality input cap makes.the.most difference to the flavour of the sound. I guess everything makes a difference, only sometimes it is.not heard.
Hi murillollirum. Which do you prefer, active or your now passive speakers.
Had a nice GTG yesterday and in which a helpfull diyer and a couple of other audiophiles came around for a listen and tune of the new active/passive setup. The SKA was on the short list as one of the amps to build for my active speakers. After a little crossover tuning with the original 2 amps I was using, the "honeybadger" and a Sony TA-F700es we were getting some decent sound. We were running with a flat freq response and with those amps I felt the need to have the response drop by around 3-4db from 100hz-20khz.
After connecting the SKA, the audio quality just lifted by many notches. The ska made any harsh glare usually associated with solid state to dissappear almost completely. At the same time no detail was lost. This amp seems to make the begining transients of a note much faster, which resulted in a more musical sounding amp. It really shined on mids and vocals imo.
A great amp I must say.
Thanks for bringing it around Repeet.
Simon
After connecting the SKA, the audio quality just lifted by many notches. The ska made any harsh glare usually associated with solid state to dissappear almost completely. At the same time no detail was lost. This amp seems to make the begining transients of a note much faster, which resulted in a more musical sounding amp. It really shined on mids and vocals imo.
A great amp I must say.
Thanks for bringing it around Repeet.
Simon
Unity gain?
Would it be possible to run SKA in unity gain? Can someone help me how to do it?
Thanks.
Would it be possible to run SKA in unity gain? Can someone help me how to do it?
Thanks.
Hi
I just bought an SKA GB150d..I'm a relative novice on DIY power amps but having read some reviews I took a chance and bought this beast
Having a few probs at the moment with the left amp but will soon have it resolved
Here are some pics of the build..Would welcome your views on the final construction..Looks very clean to me
Wondering how the GB150d will cope with the Martin Logans even though Greg says it can cope well ..does anyone have any experience in driving electrostatics like the Martin Logans ..🙂
Thanks in advance
Gibguy
BTW My system
Pre amplifier..Audio Analogue Bellini
Power amp A&R Cambridge SA200
Martin Logan LS3 electrostatic speakers
Thorens LP deck
Marantz 6005 CD
I just bought an SKA GB150d..I'm a relative novice on DIY power amps but having read some reviews I took a chance and bought this beast
Having a few probs at the moment with the left amp but will soon have it resolved
Here are some pics of the build..Would welcome your views on the final construction..Looks very clean to me
Wondering how the GB150d will cope with the Martin Logans even though Greg says it can cope well ..does anyone have any experience in driving electrostatics like the Martin Logans ..🙂
Thanks in advance
Gibguy
BTW My system
Pre amplifier..Audio Analogue Bellini
Power amp A&R Cambridge SA200
Martin Logan LS3 electrostatic speakers
Thorens LP deck
Marantz 6005 CD
Attachments
The Designer tells you the amp will drive your speakers, Why do you doubt him?
The Designer was one of our amplifier experts.
Unfortunately he got himself expelled.
Your best support will come from the Designer and his own Forum.
The Designer was one of our amplifier experts.
Unfortunately he got himself expelled.
Your best support will come from the Designer and his own Forum.
Thanks Andrew
He didn't tell me ..I read it somewhere .. I was genuinely enquiring and curious as to others experiences if any in driving electrostatic speakers with the GB150d
Why was Greg excluded? I am a newcomer to this forum and don't know the history..
Is Greg contactable ..I can't find a contact address
Is anyone out there in contact with Greg and willing to pass on his details
Thanks again for your support
KRs
Gibguy
He didn't tell me ..I read it somewhere .. I was genuinely enquiring and curious as to others experiences if any in driving electrostatic speakers with the GB150d
Why was Greg excluded? I am a newcomer to this forum and don't know the history..
Is Greg contactable ..I can't find a contact address
Is anyone out there in contact with Greg and willing to pass on his details
Thanks again for your support
KRs
Gibguy
He's just another on the growing list of positive & creative, but perhaps abrasive personalities, that has left/been expelled from diyAudio, unfortunately.
As 'niss' mentioned above, the 'SKA Audio" website will find him okay and plenty of information on this design.
As 'niss' mentioned above, the 'SKA Audio" website will find him okay and plenty of information on this design.
Member
Joined 2009
Paid Member
Unfortunately, I have experienced some immature behaviour from Greg and will not deal with him myself but his amplifier is good. Best place for support, if you have legitimately purchased his products, is to go to his forum - he does provide good support.
Did you run a wire from the input ground to star ground? For some reason the lifted ground causes problems with oscillation.