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Project: Hafler DH-101

Super Noob

Super Noob

Super Member
A year or so ago, I picked up a Pioneer SA-900 and set of Large Advents from a gentleman named Pete. Pete was very into HIFI, and we stayed in touch. Recently was asked to rebuild his DH-101 in exchange for a Marantz Model 22 in non-working state. I like challenges and was looking for a project or two so I accepted.

hafler_logo.jpg


DH-101 preamp was an early model many folks are very fond of. The following posts document the rebuild. Hope this many help someone in the future.

Initial Pics:

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Power Supply Up First.

C24 Electrolytic1000 uf / 35v Electro 1000uf 35v UPW1V102MHD Nichicon 1000uf 35v
C25 Electrolytic1000 uf / 35v Electro 1000uf 35v UPW1V102MHD Nichicon 1000uf 35v
C26 Electrolytic 100uf / 25v Electro 100uf 25V UPW1V101MPD Nichicon 100uf 35v
C27 Electrolytic 100uf / 25v Electro 100uf 25V UPW1V101MPD Nichicon 100uf 35v

D1 1N4002 1A, 200V, Standard Recovery 1N4004 On-Semi 1 Amp, 400V, Standard Recovery
D2 1N4002 1A, 200V, Standard Recovery 1N4004 On-Semi 1 Amp, 400V, Standard Recovery
D3 1N4002 1A, 200V, Standard Recovery 1N4004 On-Semi 1 Amp, 400V, Standard Recovery
D4 1N4002 1A, 200V, Standard Recovery 1N4004 On-Semi 1 Amp, 400V, Standard Recovery

Before Shots:
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ACtC-3fanA8S7sZnwXZFncxPVr9FbEYWSuQXimUOeJ9P3s7qhKyVLsYP6HyYRmLmPMstGlU8XIMDL5mzOa6DZ0lzWqm1xuFYLxaVhwizZN8XXIE0lk7WYVL6Csw9PfvEZTSAgHAzLcNUyafDDrSGxOZNRbM=w1175-h881-no


As you can see one of the traces was bypassed with a jumper.

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ACtC-3fHsp82wbiQ7u7KZxMo2-s7vM3zvyhVLeDUeDwEwK70xCCnORIUPIFOlnPDHlVnc4TyClnWzfJ0UPpsCTkkPIUVtpZ75wr5-iL12rJRkejAVYa3VQPqhhdkxYUl38aGMVSD2bwocA_bKJKGcm_Xt3o=w661-h881-no

ACtC-3f18ZVNkFnMyn3hlQwDCLNzrBLDoXhI-9fRTxsKwBiqaEjPtnNdNOnMLVv9WtxNjOpkxTA-YJoXP6FEHdagmLobqnBIFw_ZApl0_l3m_wIRMfViON5p7uJj_djEHVvTvkvWa_CZW1Zap1Z6JFvMQ8g=w661-h881-no

ACtC-3dP5q5A7iVxf_WsacWskWbeaVvMdtXzvZfkE5-LT1w4cYFA3UEX3PasyjZUaNmnV898DxFVzx3w7jznAPdO57ST_rHyfuMyh7rQhVCTy7lnGsyZV5vTizaWHjUgr77frAziavd3JJgpj4aAnC4pih8=w661-h881-no


ACtC-3foqQTEQXEdmtORj2YgAXAqPT2DMYsGI9y62cZx2wTLiAXpUYKbAXuqZsFDR01G2CJBGnmBYyWmtIks5GFglB2EKDoDB3q9mmC6OFiMnQMgyXh1mk-iFEyPP80QqRZmKTv7VvL-Z_aRaZx_RMk44HU=w1175-h881-no


ACtC-3ebpds9xcW8JH-hUT12j8swLqKBAG-Jo3NpPeVBqajAXc_cmOJUXsLFJDMnMlNYahyZS_SeaevkOIlYlu-LMREDCBt3-J7Jtj7XuLeWA5OuYj3nnk4JhsnSQfeabdhGzUJo7_u-KGl43fcni5hoO-0=w661-h881-no


Iowa Capacitors out...
 
Main Preamp Board

Right Channel
C2 Electro 10uf, 3v Tantalum (LL) B-T-B Tant 10uf 3v MKS2B044701KJC00 WIMA 4.7uf 50v Film (found dual 10uf tants for NP setup)
C3 Electro 220uf, 6v, Electrolytic Electro 220uf 6v UKA1C221MED Nichicon 220v 16v
C4 Electrol 220uf, 6v, Electrolytic Electro 220uf 6v UKA1C221MED Nichicon 220v 16v
C5 Electro (non polar) 470uf, 16v Electro 470uf 16v UES1E471MHM Nichicon 470v 25v
C6, Film, 6800 pF, 100v Film 6800pf 100v PHE426HJ4680JR05 Kemet 6800pf 250v (Polypropylene)
C7, Film, .027 uF, 100v Film .027uf 100v PHE426HJ5270JR05 Kemet .027uf 250v (Polypropylene)
C8 Electro (non polar) 10uf, 16v Electro 10uf 16v UES1E471MHM Nichicon 10uf 25v
C11 Electro 10uf, 3v Tantalum (LL) B-T-B Tant 10uf 3v MKS2B044701KJC00 WIMA 4.7uf 50v Film (found dual 10uf tants for NP setup)
C15, Film, .043 uF, 100v Film .043uf 100v ECW-F4433JL Panasonic .043uf 400v (Polypropylene)
C16, Film, .39 uF, 100v Film .39uf 100v ECW-F2394JAB Panasonic .39uf 250v (Polypropylene)
C17 Electo (non polar) 220uf, 16v Electro 220uf 16v UES1E221MHM Nichicon 220v 25v
C18, Film, .00135 uF, 100v (found .0015 uf, 100v) Film 1500pf 100v ECQE6152JF Panasonic 1500pf 630v
C19, Film, .012 uF, 100v Film .012uf 100v PHE450KK5120JR05 Kemet .012uf 400v (Polypropylene)
C20 Electro (non polar) 10uf, 16v Electro 10uf 16v UES1E471MHM Nichicon 10uf 25v

Left Channel
C2 Electro 10uf, 3v Tantalum (LL) B-T-B Tant 10uf 3v MKS2B044701KJC00 WIMA 4.7uf 50v Film (found dual 10uf tants for NP setup)
C3 Electro 220uf, 6v, Electrolytic Electro 220uf 6v UKA1C221MED Nichicon 220v 16v
C4 Electrol 220uf, 6v, Electrolytic Electro 220uf 6v UKA1C221MED Nichicon 220v 16v
C5 Electro (non polar) 470uf, 16v Electro 470uf 16v UES1E471MHM Nichicon 470v 25v
C6, Film, 6800 pF, 100v Film 6800pf 100v PHE426HJ4680JR05 Kemet 6800pf 250v (Polypropylene)
C7, Film, .027 uF, 100v Film .027uf 100v PHE426HJ5270JR05 Kemet .027uf 250v (Polypropylene)
C8 Electro (non polar) 10uf, 16v Electro 10uf 16v UES1E471MHM Nichicon 10uf 25v
C11 Electro10uf, 3v Tantalum (LL) B-T-B Tant 10uf 3v MKS2B044701KJC00 WIMA 4.7uf 50v Film (found dual 10uf tants for NP setup)
C15, Film, .043 uF, 100v Film .043uf 100v ECW-F4433JL Panasonic .043uf 400v (Polypropylene)
C16, Film, .39 uF, 100v Film .39uf 100v ECW-F2394JAB Panasonic .39uf 250v (Polypropylene)
C17 Electo (non polar) 220uf, 16v Electro 220uf 16v UES1E221MHM Nichicon 220v 25v
C18, Film, .00135 uF, 100v (found .0015 uf, 100v) Film 1500pf 100v ECQE6152JF Panasonic 1500pf 630v
C19, Film, .012 uF, 100v Film .012uf 100v PHE450KK5120JR05 Kemet .012uf 400v (Polypropylene)
C20 Electro (non polar) 10uf, 16v Electro 10uf 16v UES1E471MHM Nichicon 10uf 25v

ACtC-3dyPHWaj1frpDWh6evddAfnD6mIlId3132lkl52EIJJrjJOSNPJphSo49HCwJr6CRF0_8_dMROI-PCqGecMAOQGEwWfi6CeJSAHgJ0vCml5zEToAjzAh47niG3ZwS2AbhJIlJTBQ2kM3SjCuOe8Bked=w293-h698-no


ACtC-3emsLG7lzi68M7suzxtAxicMprbFgeNgYo6XfUeUwj9ztBOH_7WsyUGs-nFqw1KbmuCktI220zkpvzxosDdJfkThWNiG5eHa3ZJlEvewiNXkOs_xrhbhcTmCVHw2IGv5fZPAPq60s4fN2JZ9r2DezwL=w712-h424-no


Before Pics:
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ACtC-3cK1qA51mzP7y9mE1x-CgDxv3kDa3dH5zNUs4y55qafce3cg08AxO7QdRKzEtCs-wM2gEl6sDjtRQs9fUbn3uxjuiolL6Dth17fn7Ris4b3WbPgTM_sINfhTbpc-Hos_GVPzbs8omOTbQXiTVBT4GE=w1175-h881-no

ACtC-3ftJBs882z55OZRR0py-s-sXr00dlkKd-BEP3-4wGZOx5nJiVOlj7IccHTAeYI4fQpuh4sYYvm9nUl1U5ssH_EkY4-EnW7PTrQlXOKncLrXY9k8UNmQS2ElKCYujove2OHF9naWf7LPPoZbDeiPrIc=w661-h881-no


C2 & C11 found dual tants 10uF in series back to back for NP setup... this drops the uF by 50%. Elected to go with single NP WIMA 4.7uF.
ACtC-3dxppSkCBsyJcHxj0yOd73afuSIRh60bvnCflBme-NXedDek3SOlDX_sNJ0hE6kTopPQ6EyInsFyWrJn4mMpJS43gld76kWzOp3B59YNjPN8u-hMJlkRSyOA9eBLnSmoZCW6DBqUvPg2HfOjWOTY5o=w661-h881-no

ACtC-3eLoytkSBVmiN0877hPapg7jSxK4Rp8QI1SAVoNPs37wf7T9IwlOmLgSPPootyqMFfwgVSmxArTDR2sdr8WgTjGZxL38syUSrbMg6m7XlghOrb5vVl4jZ2UjYEsYD7umdgvMiSsaE5eOxHhe8LGjFU=w685-h913-no

ACtC-3e88cx2xBXDxn_bSGZ0oT901RlDsfu8amz0PrOQTdjs95BG_4qVAghQFVc5r1Hrwu9rLtNim4Tg_vagbLm49vEXethm0CSxC-o2ZU_ALlitUaTxCS7SRD8pk6UONTArlBPysnxLYGdhphjhVKNofqc=w661-h881-no

Think you get the idea... jump the pads to get 4.7 uF WIMA from point 1 to point 4.
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ACtC-3dljV8ZlxOQUgORUwR0j2A6-8hT4ZAszwHNanvF8NO-YkfQb-IbMmaM6X9C59i1a8faglmTldGBeO3rQ139Giy5MhFO8c-znz-aiRK_McdOClM7lK1MzcHgQPjKnyQduQ00xIlyJ9m4s4SzBBQIaXop=w661-h881-no


Final Shot:
ACtC-3dQrqSGvbDEkPaQoVkbe-okguQgJgSyDEIwvHkcn8sDgJJtMFxT35u-uFkXOOpOAZs1690Y6cJTJJmQEpzzF18NWwKxu05kfs5yFQHlvYA7BqtDbd2U63cFTibxYOJ5uuSdj9WhFA080qQJeP3uLRM=w661-h881-no


One of the darlington was bad...
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Q9 MPS-A65 Darlington (found MPS A63) (PNP, Vceo = 30v, Cebo 10v, HFE ~ 10000+, Ic = 500 mA, Pd = 625 mW, fT = 125 MHz (min), Pin EBC)
BC516 (On Semi) PNP Darlington, Vceo = 30v, Vebo = 10v, HFE = 30,000 min, Ic = 1 a, Pd = 625 mW, fT = 200 MHz, Pin CBE)

Q10 MPS-A13 Darlington (NPN, Vceo = 30v, Cebo 10v, HFE ~ 5000/10000, Ic = 500 mA, Pd = 625 mW, fT = 125 MHz, Pin EBC)
BC517 (On Semi) NPN Darlington, Vceo = 30v, Vebo =10v, HFE = 30,000 min, Ic = 1.2, Pd = 625 mW, fT =200 MHz, Pin CBE)

Changed Q9/Q10 in both channels.
ACtC-3e3srKJr9B0F3BQttw1zHs4Duz9DOpzDl2Aquau6Rr4mZeV8wlHodkUefg_S-NUqp0QvgvAEKmZCxIIVRuiv_oDZ3GSvqmOGjeEV3TAUiJlofmC_tYoloPyA2-aTsNHRiecSJ_uyPhmTarK7X-x3lM=w661-h881-no
 
The RCA plugs on the back and build are bit flimsy... but the folks that have these know this.

Took some time to clean them up.... not too shabby.
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ACtC-3dN4cqrmpn_0W4HmJbidTAwqNBMi4ZbgcOfjd228Hvt-rOzVmNHd-tkThk2ybqpkd0kP-bZ2g9gQU3Lw1iiyJTaZt4P4_4g8ov7Mn8stWequOvijsH82poyiOGegZGaXC3tOPboK8jyl5CfdR7cHnw=w661-h881-no


Next up time to pull the pots and clean them properly - deoxit D5 followed by F5.
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ACtC-3fl58_SP_UiciYMJ16l8K7xilPfP-Q6kSKiW905Zqm8uRinS7xNzaEqgIvjn6v3mzQEr5s_kDpuSq-1n54h3ZgfG7LZeQlcbeymrSnUN0-tPyFM3OMzhZ-zktEADx1reXOjN1D3bxgYafC564D_DVY_=w685-h913-no


Also flush the flimsy push buttons...
 
i'm glad you like your hafler. I built mine in 1979, updated a few things in the early 80s from TAA and then a few years ago i updated a few resistors to MF using this as a guide.

most use the low noise diodes (like a uf4007) in the PS.

I really like my 101 with these simple updates.
 
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rickl said:
i'm glad you like your hafler. I built mine in 1979, updated a few things in the early 80s from TAA and then a few years ago i updated a few resistors to MF using this as a guide.

most use the low noise diodes (like a 1uf4007) in the PS.

I really like my 101 with these simple updates.
Click to expand...
1N4004 and 1N4007 are the same family of diodes.... one is 400v while the other is 1000v.

Original was 200v FYI.
 
Wondering...Is your unit "deal quiet"?

EDIT: I did not intent on hi-jacking this thread. Starting my own in another forum.
 
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Apologies on dredging up an old thread, but my question pertains directly to this early type of 101:

In replacing the tantalum sets in positions C2 and C11, since the values of each cap are 10uf, and there are two back-to-back, wouldn't you want to replace it with a single 10uf film cap? I was told you cut capacitance in half when there are two caps in series. So 10uf + 10uf = 20uf Divide 20uf by 2 and you get 10uf if you'd be using a single cap replacement. Am I thinking right?
 
2 10uF in series is 5uF
2 10uF in parallel is 20uF

I think I used a 4.7uF bipolar muse or a 4.7uF mks2 film. My DIY one used a 5uF film.
 
Yep, these are in series on the board, just like the photos above. I saw one guy use two 22uf caps glued together on a different thread. Guess that was definitely wrong. I had also seen a simplified formula online that just said to take total capacitance and divide by number of caps, so in this case, this is where I came up with 10uf total. So it's the 10uf divided by the two caps, giving 5uf. Got it.
 
That definitely goes further in depth, but makes it a little more confusing maybe? Regardless, 5uf it is! I think I'll go the 4.7uf Wima film route as well as they clearly fit just fine and perform well.
 
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