AKSA's Lender Preamp with 40Vpp Output

xrk971 · 2017-11-27 10:31 am

The pricing for the preamplifier PCB with your choice of qnty 2 x daughterboards, either TH or SMT will be USD $20 per set, plus shipping cost. Shipping cost (with tracking number) will be as follows: in the USA is $5, Canada is $10, and everywhere else is $15.

Please send me PM with your PayPal address (and country I will be shipping the PCB's to) and I will send invoice.

Thanks,
X

Algar_emi · 2017-11-27 3:27 pm

PM sent with PayPal address. Thanks SB

xrk971 · 2017-11-27 3:42 pm

GB status update.

If you have not done so yet, please PM me your PayPal info, choice of TH or SMT daughterboards (qnty of sets) and country to ship to. Thanks. X

JPS64 -2 sets w/ SMT daughterboards, Paid
Algar Emi - 1 set, TH, Invoice sent
Redarc12 - 1 set, SMT or TH?
CFT - 1 set, SMT or TH?
Jacques Antoine - 1 set TH, Invoice sent
Silasmellor - 1 set THT
Bvtrinh- 1 set TH
ggetzoff - 1 set TH
tubesguy - 1 set TH
Aatto - 1 set SMT
Mordikai - 1 set TH
Johnny2Bad 1 set TH; 1 set SMT
vvs07 - 2 sets TH
Fabian85 - 1 set SMT
PCGAB - 1 Set(MB) with SMT boards.
Harry3 - 1 set MB plus TH
meanman64 - 1 set MB plus THT
Wayne1 - 1 set TH, Invoice sent
obh - 1 Set(MB) plus TH, Invoice sent

Sk8Ter · 2017-11-27 4:41 pm

hoping there will be boards available later on

I just cannot afford to build this yet, so I am hoping there will be some boards later on.

someone should start builders thead

I would like to see how you all get on with chassis etc.

xrk971 · 2017-11-27 5:24 pm

Hi JP,
Thanks so much for making the layout for us! Would you happen to have a BOM for the boards? There are some specialized jacks/swithces/etc that we could use the part numbers on. Or is it all in the Schematic already?
Thanks,
X

PJN · 2017-11-27 5:43 pm

JPS64 -2 sets w/ SMT daughterboards, Paid
Algar Emi - 1 set, TH, Invoice sent
Redarc12 - 1 set, SMT or TH?
CFT - 1 set, SMT or TH?
Jacques Antoine - 1 set TH, Invoice sent
Silasmellor - 1 set THT
Bvtrinh- 1 set TH
ggetzoff - 1 set TH
tubesguy - 1 set TH
Aatto - 1 set SMT
Mordikai - 1 set TH
Johnny2Bad 1 set TH; 1 set SMT
vvs07 - 2 sets TH
Fabian85 - 1 set SMT
PCGAB - 1 Set(MB) with SMT boards.
Harry3 - 1 set MB plus TH
meanman64 - 1 set MB plus THT
Wayne1 - 1 set TH, Invoice sent
obh - 1 Set(MB) plus TH, Invoice sent
PJN - 1 set TH

JPS64 · 2017-11-27 5:49 pm

Hi X,

see previous replies including Excel BOM. But I´ll check and publish new ones until wednesday.

JP

silasmellor · 2017-11-27 6:22 pm

This sounds like a very cool project that i look forward to building. Thanks to all three of you, AKSA, xrk971 and JPS64 for providing this resource

PM Sent

xrk971 · 2017-11-27 6:38 pm

GB Updates

JPS64 -2 sets w/ SMT daughterboards, Paid
Algar Emi - 1 set, TH, Invoice sent
Redarc12 - 1 set, TH, Invoice sent
CFT - 1 set, SMT or TH?
Jacques Antoine - 1 set TH, Paid
Silasmellor - 1 set THT, Invoice sent
Bvtrinh- 1 set TH
ggetzoff - 1 set TH
tubesguy - 1 set TH, Invoice sent
Aatto - 1 set SMT
Mordikai - 1 set TH
Johnny2Bad 1 set TH; 1 set SMT
vvs07 - 2 sets TH
Fabian85 - 1 set SMT
PCGAB - 1 Set(MB) with SMT boards, Paid
Harry3 - 1 set MB plus TH
meanman64 - 1 set MB plus THT
Wayne1 - 1 set TH, Paid
obh - 1 Set(MB) plus TH, Invoice sent
PJN - 1 set TH

manniraj · 2017-11-28 1:08 am

JPS64 -2 sets w/ SMT daughterboards, Paid
Algar Emi - 1 set, TH, Invoice sent
Redarc12 - 1 set, TH, Invoice sent
CFT - 1 set, SMT or TH?
Jacques Antoine - 1 set TH, Paid
Silasmellor - 1 set THT, Invoice sent
Bvtrinh- 1 set TH
ggetzoff - 1 set TH
tubesguy - 1 set TH, Invoice sent
Aatto - 1 set SMT
Mordikai - 1 set TH
Johnny2Bad 1 set TH; 1 set SMT
vvs07 - 2 sets TH
Fabian85 - 1 set SMT
PCGAB - 1 Set(MB) with SMT boards, Paid
Harry3 - 1 set MB plus TH
meanman64 - 1 set MB plus THT
Wayne1 - 1 set TH, Paid
obh - 1 Set(MB) plus TH, Invoice sent
PJN - 1 set TH
manniraj - 1 set TH

Johnny2Bad · 2017-11-28 1:28 am

xrk971 said:
Johnny2Bad:
Motherboard is only TH, so do you want two TH MB’s? The daughterboards come in 3 flavors: TH, SMT, and SMT metal core.

Sorry, yes, 2 MBs
1 TH daughterboards
1 SMT (FR4) daughterboards

xrk971 · 2017-11-28 3:18 am

GB status update

JPS64 -2 sets w/ SMT daughterboards, Paid
Algar Emi - 1 set, TH, Invoice sent
Redarc12 - 1 set, TH, Paid
CFT - 1 set, TH, Invoice sent
Jacques Antoine - 1 set TH, Paid
Silasmellor - 1 set THT, Paid
Bvtrinh- 1 set TH, Invoice sent
ggetzoff - 1 set TH
tubesguy - 1 set TH, Paid
Aatto - 1 set SMT, Invoice sent
Mordikai - 1 set TH
Johnny2Bad 1 set TH; 1 set SMT, Invoice sent
vvs07 - 2 sets TH
Fabian85 - 1 set SMT
PCGAB - 1 Set(MB) with SMT boards, Paid
Harry3 - 1 set MB plus TH
meanman64 - 1 set MB plus THT
Wayne1 - 1 set TH, Paid
obh - 1 Set(MB) plus TH, Invoice sent
PJN - 1 set TH
manniraj - 1 set TH, Invoice sent

bvtrinh · 2017-11-28 3:22 am

Balanced in and out

If I needed the preamplifier to have balanced in and out, would I need two of each?

xrk971 · 2017-11-28 3:38 am

bvtrinh said:
If I needed the preamplifier to have balanced in and out, would I need two of each?

Yes, I think so. I am not sure how much of the PCB would need to be modified as the inputs and outputs are single ended RCA jacks. Maybe Hugh or JP can answer.

AKSA · 2017-11-28 4:23 am

BV,

Best option is to use balanced transformers, made by Sowter, Jensen, and Lundahl. They are expensive, but the best to use because they give galvanic isolation, guarantee to stop earth loop which make hum.

Hugh

xrk971 · 2017-11-28 4:40 am

GB Status Update. 30 Motherboards ordered, so we are coming up against a limit of how many more folks can join this GB.

JPS64 -2 sets w/ SMT daughterboards, Paid
Algar Emi - 1 set, TH, Invoice sent
Redarc12 - 1 set, TH, Paid
CFT - 1 set, TH, Invoice sent
Jacques Antoine - 1 set TH, Paid
Silasmellor - 1 set THT, Paid
Bvtrinh- 1 set TH, Invoice sent
ggetzoff - 1 set TH
tubesguy - 1 set TH, Paid
Aatto - 1 set SMT, Invoice sent
Mordikai - 1 set TH
Johnny2Bad 1 set TH; 1 set SMT, Invoice sent
vvs07 - 2 sets TH
Fabian85 - 1 set SMT
PCGAB - 1 Set(MB) with SMT boards, Paid
Harry3 - 1 set MB plus TH
meanman64 - 1 set MB plus THT
Wayne1 - 1 set TH, Paid
obh - 1 Set(MB) plus TH, Invoice sent
PJN - 1 set TH
manniraj - 1 set TH, Invoice sent
Erik777 - 1 set TH, Paid
Zman01 - 1 set SMT, Paid
AKSA - 1 set SMT, Paid
xrk971 - 1 set SMT, Paid

28 sets so far, 2 remaining. But experience tells me that there will be one or two folks in the list who will not go through with it, so there are probably 3-4 sets remaining, if my estimates of no-shows works out.

bvtrinh · 2017-11-28 5:18 am

Thank you!

AKSA said:
BV,

Best option is to use balanced transformers, made by Sowter, Jensen, and Lundahl. They are expensive, but the best to use because they give galvanic isolation, guarantee to stop earth loop which make hum.

Hugh

Thank you Hugh!

Bao

xrk971 · 2017-11-28 8:53 am

I just tested this preamp as a headphone amp and it works very well. I installed a 2SA1837 as the output BJT (vs the KSA1381) and dropped Vcc to 24v and bias to 80mA across a 2.2R source resistor on the 2SA1837. Also installed 2200uF 50v output cap to get bass response lower. Listened to a bunch of tracks using DT880-250 in pseudo stereo so amp sees 125ohms load (L&R driven in parallel). It runs dead quiet.

JPS64 · 2017-11-28 9:05 am

Hi X,

do you´ve ordered Mainboard? I would do a smal modification, adding a RK ALPS potentiometer in parallel to TKD one (cheaper solution).

JP

xrk971 · 2017-11-28 9:12 am

I submitted the job about 5hrs ago, let me ask them if it's not too late to halt production.

AKSA's Lender Preamp with 40Vpp Output

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