A few ideas and links
A few ideas that you might consider... [BTW, I never saw your post]
I was generalizing on the topic, ~ why I do, what I do and why ~
I was not addressing you, directly. Only saw Ricks comment...
Tidy chassis's are important... EG. twisting AC (music carrying)
wiring and keeping it tight to the chassis. Always best to
form 'good habits', taking greater pride in your work.
Grammatical correction to above copy, each channel should have its own FEED (not 'ground') supplying each channels fuse blocks, so as not to share current path through a single wire. (Hafler, only did it the 'other way' to save time and cost) for scale of economy. TRUST ME, it makes a big difference.
Like having a .big. intake manifold and throaty 3" exhaust(s) on a hot rod... or even straight pipes... as example. Unrestricted throughput.
And .do. use a .1 film bypass on each capacitor... Actually .all. electrolytic caps in the amplifier. Reduces inductance, improves high frequencies.
You would want to use a NTC or CL branded Thermistor (not an SL)
https://www.mouser.com/ProductDetail/527-CL30
*I have used these mostly... depending on use / loading.
This HEXFRED is hard to beat for the money.
~ Far better ~ than block type ~ under 7.00
https://www.mouser.com/ProductDetail/IXYS/FBE22-06N1?qs=sGAEpiMZZMtQ8nqTKtFS/KGlmTW84eZInlKWqkL3/AE=
I have used many of them... In every build the past 8 years...
A great barrier terminal block, to hold the rectifier...
https://www.mouser.com/ProductDetai...ntO7gZZwOWBuNtD91UGvyGnTz4NZTgGNrVluJ2p3cjA==
A very good sounding (affordable) capacitor. Compact, dense storage.
https://www.mouser.com/ProductDetai...=sGAEpiMZZMtZ1n0r9vR22RK/v8p28JxY1SGoEdCM/oA=
Ring terminals will make for a better interface and tidy wiring.
I use 10 gauge solid core copper wire for the star ground.
https://www.lowes.com/pd/Utilitech-20-Count-Ring-Wire-Connectors/999953406
Ditch those old stock tabs...
I like Bobs idea, I also want to try copper block at some point...
This is a good starting point... what I use on all basic amp builds.
Feel free to p/m me directly, as well, if you need any further insight.
This will make for a great amplifier core...
A few ideas that you might consider... [BTW, I never saw your post]
I was generalizing on the topic, ~ why I do, what I do and why ~
I was not addressing you, directly. Only saw Ricks comment...
Tidy chassis's are important... EG. twisting AC (music carrying)
wiring and keeping it tight to the chassis. Always best to
form 'good habits', taking greater pride in your work.
Grammatical correction to above copy, each channel should have its own FEED (not 'ground') supplying each channels fuse blocks, so as not to share current path through a single wire. (Hafler, only did it the 'other way' to save time and cost) for scale of economy. TRUST ME, it makes a big difference.
Like having a .big. intake manifold and throaty 3" exhaust(s) on a hot rod... or even straight pipes... as example. Unrestricted throughput.
And .do. use a .1 film bypass on each capacitor... Actually .all. electrolytic caps in the amplifier. Reduces inductance, improves high frequencies.
You would want to use a NTC or CL branded Thermistor (not an SL)
https://www.mouser.com/ProductDetail/527-CL30
*I have used these mostly... depending on use / loading.
This HEXFRED is hard to beat for the money.
~ Far better ~ than block type ~ under 7.00
https://www.mouser.com/ProductDetail/IXYS/FBE22-06N1?qs=sGAEpiMZZMtQ8nqTKtFS/KGlmTW84eZInlKWqkL3/AE=
I have used many of them... In every build the past 8 years...
A great barrier terminal block, to hold the rectifier...
https://www.mouser.com/ProductDetai...ntO7gZZwOWBuNtD91UGvyGnTz4NZTgGNrVluJ2p3cjA==
A very good sounding (affordable) capacitor. Compact, dense storage.
https://www.mouser.com/ProductDetai...=sGAEpiMZZMtZ1n0r9vR22RK/v8p28JxY1SGoEdCM/oA=
Ring terminals will make for a better interface and tidy wiring.
I use 10 gauge solid core copper wire for the star ground.
https://www.lowes.com/pd/Utilitech-20-Count-Ring-Wire-Connectors/999953406
Ditch those old stock tabs...
I like Bobs idea, I also want to try copper block at some point...
This is a good starting point... what I use on all basic amp builds.
Feel free to p/m me directly, as well, if you need any further insight.
This will make for a great amplifier core...
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An example of chassis pan rebuild (cleaning comments)
My very first Hafler 500 - the Hafler 500 crud amp.
I actually got sick for 2 days after cleaning this amp.
E. I., Environmental (exposure) Illness - literally.
*as reference to earlier post...
Chernobyl - Fukushima rads, God only knows
what was coming off of it... off gassing crud...
**no longer so... it took alcohol to clean it.
I wore nitrile gloves as a protective barrier ~ and ~
I used a leaf blower and brush outside, to clean
dust out, I did not want to even breath any of it
into my body, I still got sick...
This was the way I got it, I was so freaked out.
Looked like it had been in a barn for years...
it even stunk - it was wretched...
*notice how discolored the heat sink was.
Image 2, there is a partially cleaned fin.
Tidy wiring dress is easy... stock wiring
would not have even worked.
A before and after... (image 2) only 'listened to'
it for 6 hours, let is stabilize, set bias and DC offset
only to determine ~ it had to be(come) dual mono ~
it did not sound that good, not as good as
my overbuilt Hafler 220, believe it or not.
To think that image 5 was my 5th build iteration,
as I gradually worked in stages, checking the
process, as it got better along the way.
I had 3x the money in parts, as the chassis cost
of the DH500 crud amp... Actually liked it better
than my 9,500.00 Mark Levinson No.336
which I sold soon after...
I re-positioned the 5 way binding posts,
...making for a super tidy chassis...
looking like dual AMG exhaust tips
Shorter, more direct wire runs, no protection
relay or speaker fuses. This amp is amazing.
I plan to compare the new P230 mono amps
to this amp, shortly... after they are broken in.
My very first Hafler 500 - the Hafler 500 crud amp.
I actually got sick for 2 days after cleaning this amp.
E. I., Environmental (exposure) Illness - literally.
*as reference to earlier post...
Chernobyl - Fukushima rads, God only knows
what was coming off of it... off gassing crud...
**no longer so... it took alcohol to clean it.
I wore nitrile gloves as a protective barrier ~ and ~
I used a leaf blower and brush outside, to clean
dust out, I did not want to even breath any of it
into my body, I still got sick...
This was the way I got it, I was so freaked out.
Looked like it had been in a barn for years...
it even stunk - it was wretched...
*notice how discolored the heat sink was.
Image 2, there is a partially cleaned fin.
Tidy wiring dress is easy... stock wiring
would not have even worked.
A before and after... (image 2) only 'listened to'
it for 6 hours, let is stabilize, set bias and DC offset
only to determine ~ it had to be(come) dual mono ~
it did not sound that good, not as good as
my overbuilt Hafler 220, believe it or not.
To think that image 5 was my 5th build iteration,
as I gradually worked in stages, checking the
process, as it got better along the way.
I had 3x the money in parts, as the chassis cost
of the DH500 crud amp... Actually liked it better
than my 9,500.00 Mark Levinson No.336
which I sold soon after...
I re-positioned the 5 way binding posts,
...making for a super tidy chassis...
looking like dual AMG exhaust tips
Shorter, more direct wire runs, no protection
relay or speaker fuses. This amp is amazing.
I plan to compare the new P230 mono amps
to this amp, shortly... after they are broken in.
Attachments
Unparalled Beast of the XL600
The effects the you experienced first hand ARE NOT IMAGINED, greatly extended with dual mono P/S and far better .modern. front end driver boards.
The Hafler XL600 ~ BLEW MY MIND ~ the first time I heard it (modified of course) I would have really like to hear it side by side my old Levinson 336, conversely... which I am glad that I sold... these particular Hafler based amps correctly "optimized" ~ WILL SERIOUSLY CHALLENGE ~ many modern amps, both Vacuum Tube and Solid State [and do read between my lines… as unspoken expression] *these lateral MOSFETS rule... driven with a 'modern front end'.
NOTE OF CAUTION: to XL280 and XL600 owners, the stock PC-40 driver boards are showing their age, with unsatisfactory DC offset common to most amps. IE. they have no DC offset adjustment and the FETS are unobtainable... part of why I swapped out my driver boards immediately, before even auditioning them, at lenght stock... Over 600 millivolts on one channel, immediately .after. relay released!!!
...Quoting myself, how about that... a worthy repeat for background (and emphasis) the Maggies had *cone type bass* with, NO overhang... it controlled these bass panels as I never experienced.
The Hafler 500 and 600s in more revealing FULL RANGE systems, have an UNPARALLELED WEIGHT AND BODY (apart from [unrelated to?] power ratings) due to the higher B+ voltages 85wvdc ~vs~ 65wvdc, that is very apparent.
One of my favorite amp speaker combinations was with the MC500 driving my .modest. Spica TC-60 speakers. I was always careful in driving the combo (not to overheat the voice coils) on the 6.5 inch drivers... I watched or rode the volume control, or maximum drive levels. *I realize, it makes no sense... a modest, non full range speaker, with humongous amp, as a pairing.
A qualifier...
**the 500 based amps driving my Silverline SR17S, with massive overhung Dynaudio voice coils, on the superlative 17WLQ mid woofer and Esotar T330D tweeters, are absolutely STUNNING!!! A much more appropriate amp/speaker pairing, in price and performance. *SR17S will take any amount of power I throw at them... I get uncomfortable, before possibly clipping (with any of my) amps, with combined efficiency and power handling.
I eventually plan to Bi-Amp the Maggies with the Musical Concepts PA7 loaded MC500 and MC600s... they both sound so good... are a breakthrough in transparency... once I replace the stock ...noisy fan... on the XL600, which effectively stifled my interest for now.
The P230 mono amps with (my 3rd set of) PA7 driver boards, now breaking in, will take about a month... have utterly captivated my listening experiences, with Silverline SR17S... which effectively displaced prior 500-600 work efforts, driving my interests, leading to the concept of the P230 mono build...
*the most apparent and serious, audible refinement with the [break through?] TP-202 power transformer is most likely what is the source to the effortless ease, and amazing sense of drive, I am hearing... Too early to tell, and be truly objective at this point.
The effects the you experienced first hand ARE NOT IMAGINED, greatly extended with dual mono P/S and far better .modern. front end driver boards.
The Hafler XL600 ~ BLEW MY MIND ~ the first time I heard it (modified of course) I would have really like to hear it side by side my old Levinson 336, conversely... which I am glad that I sold... these particular Hafler based amps correctly "optimized" ~ WILL SERIOUSLY CHALLENGE ~ many modern amps, both Vacuum Tube and Solid State [and do read between my lines… as unspoken expression] *these lateral MOSFETS rule... driven with a 'modern front end'.
NOTE OF CAUTION: to XL280 and XL600 owners, the stock PC-40 driver boards are showing their age, with unsatisfactory DC offset common to most amps. IE. they have no DC offset adjustment and the FETS are unobtainable... part of why I swapped out my driver boards immediately, before even auditioning them, at lenght stock... Over 600 millivolts on one channel, immediately .after. relay released!!!
...Quoting myself, how about that... a worthy repeat for background (and emphasis) the Maggies had *cone type bass* with, NO overhang... it controlled these bass panels as I never experienced.
The Hafler 500 and 600s in more revealing FULL RANGE systems, have an UNPARALLELED WEIGHT AND BODY (apart from [unrelated to?] power ratings) due to the higher B+ voltages 85wvdc ~vs~ 65wvdc, that is very apparent.
One of my favorite amp speaker combinations was with the MC500 driving my .modest. Spica TC-60 speakers. I was always careful in driving the combo (not to overheat the voice coils) on the 6.5 inch drivers... I watched or rode the volume control, or maximum drive levels. *I realize, it makes no sense... a modest, non full range speaker, with humongous amp, as a pairing.
A qualifier...
**the 500 based amps driving my Silverline SR17S, with massive overhung Dynaudio voice coils, on the superlative 17WLQ mid woofer and Esotar T330D tweeters, are absolutely STUNNING!!! A much more appropriate amp/speaker pairing, in price and performance. *SR17S will take any amount of power I throw at them... I get uncomfortable, before possibly clipping (with any of my) amps, with combined efficiency and power handling.
I eventually plan to Bi-Amp the Maggies with the Musical Concepts PA7 loaded MC500 and MC600s... they both sound so good... are a breakthrough in transparency... once I replace the stock ...noisy fan... on the XL600, which effectively stifled my interest for now.
The P230 mono amps with (my 3rd set of) PA7 driver boards, now breaking in, will take about a month... have utterly captivated my listening experiences, with Silverline SR17S... which effectively displaced prior 500-600 work efforts, driving my interests, leading to the concept of the P230 mono build...
*the most apparent and serious, audible refinement with the [break through?] TP-202 power transformer is most likely what is the source to the effortless ease, and amazing sense of drive, I am hearing... Too early to tell, and be truly objective at this point.
Attachments
I have bought stranded silver plated copper wire with PTFE insulation from Apexjr.com on a number of occasions. He sells it by the foot in various colors and gauges. I have a bunch of older spools of Belden PTFE insulated silver plated copper stranded wire and the Apex Jr wire seems to be of comparable quality.
Probably the only caveat is that you can shop online but have to phone in your order, he doesn't have an online cart/checkout system on his website. If you're not familiar with Apex Jr he also lists in the vendor forums here.
It'll be a bit more expensive than buying it out of China, but will probably arrive much faster.
thermal breakers
This is what i found
calco ksd301 series,
KSD301 Series Bimetal Thermostat - Calco Electric
Thanks for mentioning Apexjr.com, looks to have a good supply so I do not have to wait for slow China delivery service.
This is what i found
calco ksd301 series,
KSD301 Series Bimetal Thermostat - Calco Electric
Thanks for mentioning Apexjr.com, looks to have a good supply so I do not have to wait for slow China delivery service.
Last edited:
No to both observations.
DH-500 evaluation is not yet complete, but initial results are encouraging. The DH-500 is a somewhat different animal, in that it uses a fan and a different physical design. If the new design/board works with the DH-500 it is just icing on the cake.
This is still certainly a DH-200/DH-220 Mods thread because the DH-220C is certainly a mod of the DH-220.
Cheers,
Bob
Thank you Ozark HiFi Doctor for your detailed information, fortunately I got derailed last weekend and didn't order parts, I will likely follow most if not all of your suggestions.... Though I was hoping to do a Digikey cart, but I can swap for Mouser if I don't find the stuff I need at DK.
rsavas, sorry for mentioning the XL600 in this 200/220 thread, it was just a reference point... and I guess our passion for audio is showing a bit... I promise not to hijack.
I am glad to report, as a DH200/220 thread it is functioning well, I got just the information I was looking for!
Thanks everyone, I will report back when I have done the work, though it may take some time.
rsavas, sorry for mentioning the XL600 in this 200/220 thread, it was just a reference point... and I guess our passion for audio is showing a bit... I promise not to hijack.
I am glad to report, as a DH200/220 thread it is functioning well, I got just the information I was looking for!
Thanks everyone, I will report back when I have done the work, though it may take some time.
No problem ToneMonkey2, or Ozark, I just thought that DH-500 mods deserve a thread of their own, as Bob has eluded too, "The DH-500 is a somewhat different animal, in that it uses a fan and a different physical design".
With separate DH-500 and XL600 threads, it allow discussions specific to those models and that information does not get mixed up this thread. Mixing the models up can lead to confusion for some members as they might not know what mods apply to what models, kinda common sense imo.
What is so hard with creating a "Hafler DH-500 mods" thread? I just searched, one does not exist. I can create one, but I do not own one so I have little to add. Best for someone like you or Ozark to create since you guys have them and have information to add.
eace:
Rick
With separate DH-500 and XL600 threads, it allow discussions specific to those models and that information does not get mixed up this thread. Mixing the models up can lead to confusion for some members as they might not know what mods apply to what models, kinda common sense imo.
What is so hard with creating a "Hafler DH-500 mods" thread? I just searched, one does not exist. I can create one, but I do not own one so I have little to add. Best for someone like you or Ozark to create since you guys have them and have information to add.
eace:Rick
Last edited:
Maybe an “ultimate DH500 mod” thread, and highlight the new design C boards, assuming they would be applicable to that configuration.
Or just a separate thread dedicated to this exciting new design.
I have one that has had the outputs, large caps replaced, would be a great candidate I suppose. I’m not using it after it developed a hum on one channel one day, and shut it down before anything really bad happened.
Or just a separate thread dedicated to this exciting new design.
I have one that has had the outputs, large caps replaced, would be a great candidate I suppose. I’m not using it after it developed a hum on one channel one day, and shut it down before anything really bad happened.
Just FYI:
I found a thermal breaker on one of the heatsinks in my DH-200 that looked "crispy" (well, one wire connection is burnt... don't think that was me 40 years ago!).
The sensor -- made by Elmwood Sensors had this number: 87-232 167 80/J
I couldn't find out anything definitive about this until I learned that Elmwood was absorbed by Honeywell and contacted them. Elmwood is no more and the sensor has been discontinued. But I did learn that the NC sensor opened when the temperature reached 167 degrees Fahrenheit (cf the "167" in the model number - thanks anatech) and closed again when the temperature fell to 120 degrees or so.
Honeywell says they have a suitable replacement -- 2455R--00820923 -- but anyone wanting these would have to place an order as there is no stock at the usual suspects.
I did find a listing at Electrosonic in Toronto:
2455R-00820923 HONEYWELL | Electro Sonic
Of course I cannot use 25 of these and I can only guess at the interest level of Hafler DH-200 modifiers... like you. If any of you get some of these... I could use 2!
Hope this helps.
I found a thermal breaker on one of the heatsinks in my DH-200 that looked "crispy" (well, one wire connection is burnt... don't think that was me 40 years ago!).
The sensor -- made by Elmwood Sensors had this number: 87-232 167 80/J
I couldn't find out anything definitive about this until I learned that Elmwood was absorbed by Honeywell and contacted them. Elmwood is no more and the sensor has been discontinued. But I did learn that the NC sensor opened when the temperature reached 167 degrees Fahrenheit (cf the "167" in the model number - thanks anatech) and closed again when the temperature fell to 120 degrees or so.
Honeywell says they have a suitable replacement -- 2455R--00820923 -- but anyone wanting these would have to place an order as there is no stock at the usual suspects.
I did find a listing at Electrosonic in Toronto:
2455R-00820923 HONEYWELL | Electro Sonic
Of course I cannot use 25 of these and I can only guess at the interest level of Hafler DH-200 modifiers... like you. If any of you get some of these... I could use 2!
Hope this helps.
Honeywell has just suggested another candidate that is available in small quantities:
"Let's try the 3455RC 01000230. It has open on rise contacts and they open when the temperature rises to 165°F and re-closes when the temperature drops to 135°F. "
Is there any issue with this sensor? Is it suitable?
"Let's try the 3455RC 01000230. It has open on rise contacts and they open when the temperature rises to 165°F and re-closes when the temperature drops to 135°F. "
Is there any issue with this sensor? Is it suitable?