[b0bb]

Hi @b0bb, thank you for your suggestions and advises! I really appreciate them.

Problem with no sound after power up resolved itself after few days... hmmm. will see what will happen.

Epcos capacitors are by customs now and I'm waiting for delivery.

I'm not after Harman curve, I find it to bass heavy and unresolving. Qudelix5k has support for EQ and autoeq tried it and disabled it. I'm trying to avoid EQ when possible. HFM Arya FR curve is not prefect but I like its sound from H20.

Now I'm listening to OP1656 OP AMPs and trying to make my conclusion on it It sounds different that default OP AMPs.

Use another method to draw extra power from the amp , EQ is an easy method.

That said the Kalimba DSP is the Qudelix5k is not doing proper justice to AutoEQ, it is a 15 year old, low cost consumer grade design Qualcomm recycled from CSR.
It has none of the modern high performance DSP features like vector processing (AVX, Neon) and fused-multiply-add optimizations and is quite slow at 100MHz, tops out at 64 MIPS

Qudelix made mattters worse by making the 32bit device work on 64bit data so it 2x slower than normal, this limits the amount of processing it can perform.

Not surprised at the unpleasant outcome you experienced.

If you are willing to try again, a modern PC. with the proper DSP software gives a better account of AutoEQ's capability like convolution, it is miles ahead of a simple ParametricEQ's capability when provided with sufficient computation resources.
It opens the possibility to add a GPU to bring thousands of high-speed processing cores to the table.

 

[migo]

Use another method to draw extra power from the amp , EQ is an easy method.

That said the Kalimba DSP is the Qudelix5k is not doing proper justice to AutoEQ, it is a 15 year old, low cost consumer grade design Qualcomm recycled from CSR.
It has none of the modern high performance DSP features like vector processing (AVX, Neon) and fused-multiply-add optimizations and is quite slow at 100MHz, tops out at 64 MIPS

Qudelix made mattters worse by making the 32bit device work on 64bit data so it 2x slower than normal, this limits the amount of processing it can perform.

Not surprised at the unpleasant outcome you experienced.

If you are willing to try again, a modern PC. with the proper DSP software gives a better account of AutoEQ's capability like convolution, it is miles ahead of a simple ParametricEQ's capability when provided with sufficient computation resources.
It opens the possibility to add a GPU to bring thousands of high-speed processing cores to the table.

Hi @b0bb, thank you for suggestions Any suggestions for good DSP SW on Linux? I see you are really well informed and dedicated in this hobby. Epcos caps arrived today. Is it possible to provide me with pns. of WIMA polypropylene caps you changed in your H20? If its OK for you of course. I would like to modify my H20 to get best of it like you. Is there any good alternative to Sparkos voltage regulators you have used?

Thank you in advance! Kind regards, Milan

 

[b0bb]

Hi @b0bb, thank you for suggestions Any suggestions for good DSP SW on Linux? I see you are really well informed and dedicated in this hobby. Epcos caps arrived today. Is it possible to provide me with pns. of WIMA polypropylene caps you changed in your H20? If its OK for you of course. I would like to modify my H20 to get best of it like you. Is there any good alternative to Sparkos voltage regulators you have used?

Thank you in advance! Kind regards, Milan

Wima caps are MKP2, Mouser sells them
https://www.mouser.com/ProductDetail/WIMA/MKP2D031501H00JSSD?qs=ISKKXg98%2B1nrJXk5GuldFQ==

The DSP software I use is HQPlayer Embedded, this is the DSP engine minus the GUI and cutdown library manager.
Free alternatives like SOX exist but I have not been all that satisfied, DSP tuning for audio is a subject matter left to the experts.
HQPlayer is already complicated with its pre-configured filters.

The cost is a reflection on the work the developer is continuing to put into improving the package.

The alternative to Sparkos is Belleson, price is about the same so it depends on who has the bigger sale and when.
Gustard used the 78xx/79xx variant from New Japan Radio (NJR) on my H20, this is already very good.
Need to go to a semi-discrete to beat it.

NJR also makes the MUSES series of audio optimized opamps and volume controllers.

 

[migo]

Wima caps are MKP2, Mouser sells them
https://www.mouser.com/ProductDetail/WIMA/MKP2D031501H00JSSD?qs=ISKKXg98%2B1nrJXk5GuldFQ==

The DSP software I use is HQPlayer Embedded, this is the DSP engine minus the GUI and cutdown library manager.
Free alternatives like SOX exist but I have not been all that satisfied, DSP tuning for audio is a subject matter left to the experts.
HQPlayer is already complicated with its pre-configured filters.

The cost is a reflection on the work the developer is continuing to put into improving the package.

The alternative to Sparkos is Belleson, price is about the same so it depends on who has the bigger sale and when.
Gustard used the 78xx/79xx variant from New Japan Radio (NJR) on my H20, this is already very good.
Need to go to a semi-discrete to beat it.

NJR also makes the MUSES series of audio optimized opamps and volume controllers.

Hi @b0bb, I need a bit clarification, you replaced 12 pcs. WIMA MKS 0.1uF caps with 8 pcs. WIMA MKP2 0.15uF caps? Or there are some caps mounted on the opposite PCB side that are not seen on your photos?

I wanted to order RIFA PHE450 0.1uF caps, but search only references to KEMET PHE450 caps:

https://eu.mouser.com/ProductDetail/KEMET/PHE450HA6100JR05?qs=PoZJcSwa6Dx41Jesle6OEQ==

Can those be used too?

I've searched for voltage regulators, but have hard times to find some Sparkos or Belleson here in EU. My H20 has installed NJR 78xx/79xx too.

Thank you for your help!

Milan

 

[b0bb]

Hi @b0bb, I need a bit clarification, you replaced 12 pcs. WIMA MKS 0.1uF caps with 8 pcs. WIMA MKP2 0.15uF caps? Or there are some caps mounted on the opposite PCB side that are not seen on your photos?

I wanted to order RIFA PHE450 0.1uF caps, but search only references to KEMET PHE450 caps:

https://eu.mouser.com/ProductDetail/KEMET/PHE450HA6100JR05?qs=PoZJcSwa6Dx41Jesle6OEQ==

Can those be used too?

I've searched for voltage regulators, but have hard times to find some Sparkos or Belleson here in EU. My H20 has installed NJR 78xx/79xx too.

Thank you for your help!

Milan

It is a 1:1 replacement, mark out the picture where you think it is missing, it may be on the other side.

RIFA was acquired by Kemet.
The mouser link works.

Get the Sparkos from Audiophonics in France or contact Sparkos directly for the list of resellers in the Eurozone.
https://www.audiophonics.fr/en/216_sparkos-labs

 

[migo]

It is a 1:1 replacement, mark out the picture where you think it is missing, it may be on the other side.

here is picture of four caps that are missing on your posted image. Maybe it was image of unfinished work But want to be sure.

Change of value from 0.1u to 0.15u is intended?

RIFA was acquired by Kemet.
The mouser link works.

Get the Sparkos from Audiophonics in France or contact Sparkos directly for the list of resellers in the Eurozone.
https://www.audiophonics.fr/en/216_sparkos-labs

Thank you, I'll try to order them. EDIT: ordered +15 and -15 ones. Thank you for link!

Milan

 

[b0bb]

here is picture of four caps that are missing on your posted image. Maybe it was image of unfinished work But want to be sure.

Change of value from 0.1u to 0.15u is intended?




Thank you, I'll try to order them. EDIT: ordered +15 and -15 ones. Thank you for link!

Milan

I used 0.15uF, the remaining 4 are on the other side of the board

 

[migo]

I used 0.15uF, the remaining 4 are on the other side of the board

Thank you @b0bb, I've ordered 0.1uF and 0.15uF too. I'll put 0.15uF in as you first and when will be not satisfied I'll change them for 0.1uF. Is this increased capacitance responsible for sonic change you described or it is more change of C type to PP?

 

[b0bb]

Thank you @b0bb, I've ordered 0.1uF and 0.15uF too. I'll put 0.15uF in as you first and when will be not satisfied I'll change them for 0.1uF. Is this increased capacitance responsible for sonic change you described or it is more change of C type to PP?

The sonic changes is the result of using PP instead of mylar.
I expect 0.1uF vs 0.15uF differences to be minor.

 

[migo]

The sonic changes is the result of using PP instead of mylar.
I expect 0.1uF vs 0.15uF differences to be minor.

Hi @b0bb. I've received MKP2 PP caps today, but it is a bit different pn. MKP2D031501H00JSSD vs MKP2D031501H00JO00. They are a bit smaller. It should be OK I think, or not? Thank you!

 

[b0bb]

Hi @b0bb. I've received MKP2 PP caps today, but it is a bit different pn. MKP2D031501H00JSSD vs MKP2D031501H00JO00. They are a bit smaller. It should be OK I think, or not? Thank you!

Check WIMA's data sheet for the specifics.
Looks like the same cap to me.

 

[migo]

Check WIMA's data sheet for the specifics.
Looks like the same cap to me.

Hi @b0bb! I'm doing on your modification, one more question. Have you changed this two Mylars too, when yes for 0.15uF?

Thank you!

 

[b0bb]

Hi @b0bb! I'm doing on your modification, one more question. Have you changed this two Mylars too, when yes for 0.15uF?

Thank you!

Yes. I put them on the underside.

 

[migo]

Yes. I put them on the underside.

Thank you @b0bb I've not changed that two. Hopefully it will not harm that much. All other mods you have published are in. There was no thermal grease under voltage stabilizers in my unit, I've applied under Sparkos generic one.

Not so nice aligned like like you, but works. Your skills are on another level! I'll let it settle for few days to make conclusions. First impression is that bass slam is better in low volumes I'm listening to.

Thank you for sharing your mods!

 

[b0bb]

Thank you @b0bb I've not changed that two. Hopefully it will not harm that much. All other mods you have published are in. There was no thermal grease under voltage stabilizers in my unit, I've applied under Sparkos generic one.

Not so nice aligned like like you, but works. Your skills are on another level! I'll let it settle for few days to make conclusions. First impression is that bass slam is better in low volumes I'm listening to.

Thank you for sharing your mods!

Give it a few weeks to settle in, the electrolytics especially