Updated first page.
Purchase parts with one click from mouser ->> https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=1f37a45393
Regards,
Tibi
Purchase parts with one click from mouser ->> https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=1f37a45393
Regards,
Tibi
Please be careful with the choice of the OPA1641! Ithink you will need SOIC, ( OPA1641AID/R ) .Updated first page.
Purchase parts with one click from mouser ->> https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=1f37a45393
Not the one mentioned in the link, that Tibi provided.
Operational Amplifiers - Op Amps Single Automotive Sound-Plus High-Performance, JFET-Input Audio Op Amps 8-VSSOP
I have updated documentation on GitHub. Here is a copy/paste:Thanks Tibi, I plan to order soon. I notice that KSC1845FTA and BS250P are on backorder with long lead times, are there alternate parts?
Selecting alternative parts
With current component shortage, it may happen that some parts listed in BOM to be unavailable, here are few alternative recommendations:
R16 - use a metal film resistor
C7 - use a good polypropylene made by Mundorf, Epcos, Vishay, CDC,
U1 - following opamps can be used and will offer different sonic signatures: LME49710, LME49990, OPA604, OPA134, NE5534. Do not use TL071, TL081, LM301, LM741.
Q2 and Q3 - use transistors with Vce >= 65V & hFE>=100 : 2N5401 / 2N5550
Q7 and Q12 - other transistors that may be used are: KSC1845, 2N4401, BC546 / BC547 / BC548 / BC549 / BC550 - use the one with A termination for Q7 and C termination for Q12.
C1 - this must be silver-mica or at least polystyrene.
Q1- KSA992, 2N4403, BC556C, BC557C, BC558C, BC559C, and BC560C
C10 - silver-mica or ceramic NP0
R26, R27, R28 - these must be non-inductive resistors. MILLS make some good ones.
C17 - in this order: polystyrene, teflon, foil polypropilene, metalised polypropylene.
Q5 and Q6 - following pair replacements may be used with excellent performance: FQP3P50/FQP4N80; FQP4P40/FQP5N60
Q15,Q16,Q17,Q18 - following pairs can be used with modest performance IRFP9240/IRFP240; 2SJ201/2SK1530; 2SJ118/2SK413; 2SJ119/2SK414.
Instead BS250 you may use ZVP3306A
When you use any replacement, please take care on part pinout.
Regards,
Tibi
Last edited by a moderator:
Please be careful with the choice of the OPA1641! Ithink you will need SOIC, ( OPA1641AID/R ) .
Not the one mentioned in the link, that Tibi provided.
Operational Amplifiers - Op Amps Single Automotive Sound-Plus High-Performance, JFET-Input Audio Op Amps 8-VSSOP
Thank you for this observation !
I have corrected mouser project list.
Regards,
Tibi
Tibi,Hi Ed,
It will perform better ? For sure, Yes.
It will sound better ? Maybe, because depends on your source, your cabling, your room etc.
Adding more output devices will decrease amplifier output impedance and therefore increase amplifier capability to deliver more current in a low impedance.
Adding more output devices will make amplifier "more powerful" at lower impedances and increase his capability to drive complex audiophile speakers , including ESL.
For example at same +/-50V and 1KHz, an amplifier (here I do not talk about Q17) may have:
1. With one pair
- 100W in 8ohm
- 120W in 4 ohm
- 120W in 2 ohm
2. With two pairs
- 100W in 8ohm
- 180W in 4ohm
- 300W in 2 ohm
Having an amplifier with very low output impedance make sense even you have small bookshelf speakers.
Q17 achieve this by using high transconductance mosfets. One pair already drive a wide range of speakers very well. Two pairs is for audiophiles who look for the best at given price.
Regards,
Tibi
What is the maximum power that can be obtained from this amplifier, in a bridge connection at a supply voltage of +-50 volts (speakers of 4 ohms)? Of course, in this case, two pairs of output transistors are used.
Hey there, i am planning on building my first amp and this seems to be a nice project. I have heard once the original and was quite impressed, so i can't wait to listen this little beast !
Approximately, How much would it cost for the total project, psu/main board and an enclosure ?
Also, i cannot find the link for the mouser psu project buying list !
Approximately, How much would it cost for the total project, psu/main board and an enclosure ?
Also, i cannot find the link for the mouser psu project buying list !
@julienfesty
Entire project is on GitHub, power supply BOM is there also.
Total cost is up to your budget and the implementation you choose.
Enclosure is not yet documented.
Regards,
Tibi
Entire project is on GitHub, power supply BOM is there also.
Total cost is up to your budget and the implementation you choose.
Enclosure is not yet documented.
Regards,
Tibi
Power supply BOM
https://github.com/tvicol/Q17-a-QUAD405-audiophile-approach/blob/main/BOM_PS.md
Regards,
Tibi
https://github.com/tvicol/Q17-a-QUAD405-audiophile-approach/blob/main/BOM_PS.md
Regards,
Tibi
For active power supply I have created a new project list on mouser https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=b925207353
Does not include synchronous rectifiers and optional decoupling MKP.
Regards,
Tibi
Does not include synchronous rectifiers and optional decoupling MKP.
Regards,
Tibi
Super, thanks a lot for the answer. I admire you dedication and hard work !@julienfesty
Entire project is on GitHub, power supply BOM is there also.
Total cost is up to your budget and the implementation you choose.
Enclosure is not yet documented.
Regards,
Tibi
Hi Tibi,
Just to let you know the pcb’s arrived this morning. The Pcb manufacturing quality is the best I’ve seen in a long while. Very impressed. I will order parts now from mouser link. So far very straight forward. Thanks also for your commitment to making this work so simply.
Just to let you know the pcb’s arrived this morning. The Pcb manufacturing quality is the best I’ve seen in a long while. Very impressed. I will order parts now from mouser link. So far very straight forward. Thanks also for your commitment to making this work so simply.
The best way is to order transformer directly at manufacturer.
For my projects I order at https://petra-toroid.ro/?lang=en they ship worldwide.
How to order:
If your mains are 220-240Vac, you may order a trafo here https://www.audiophonics.fr/en/toroidal-transformers/toroidal-transformer-300va-2x38v-p-5548.html
Regards,
Tibi
For my projects I order at https://petra-toroid.ro/?lang=en they ship worldwide.
How to order:
- go to https://petra-toroid.ro/contact/?lang=en use form or email
- mention that you want to order one or two 300VA trafo
- primary 115Vac or 230Vac, depending on the mains voltage in your region
- 2 separate 36Vac secondaries
- optional magnetic shielding
- mention that application will be for audio
If your mains are 220-240Vac, you may order a trafo here https://www.audiophonics.fr/en/toroidal-transformers/toroidal-transformer-300va-2x38v-p-5548.html
Regards,
Tibi
For US and Canada, Plitron now Noratel made some great transformers, used by many very top high-end manufacturers.
Mail them.
For EU https://sklep.toroidy.pl
Regards,
Tibi
Mail them.
For EU https://sklep.toroidy.pl
Regards,
Tibi
This order is I assume doubled up in full for stereo pair of boards?. Do you have a similar list for the smd version Tibi?Updated first page.
Purchase parts with one click from mouser ->> https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=1f37a45393
Regards,
Tibi
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