De Havilland Tape Preamp

Audiophile Bill · Jun 1, 2018

Dear All,

I just recently acquired a beautiful mint 1950s Philips EL3501 transport and now looking to acquire a tape preamp. I thought the logical choice to get me in the game without spending a bomb is the De Havilland. Anyone got experience of this and how does it stac up versus the Doshi etc?

Best.

Kcin · Jun 1, 2018

I have one.

I have never compared it to a Doshi although I've heard a Doshi under show conditions. I'm still evaluating mine even though I've had it for some time. Just not enough hours on it.

Bruce B · Jun 1, 2018

I had it for a few weeks with my Studer. It picked every radio station known!!

Audiophile Bill · Jun 2, 2018

Bruce B said:
I had it for a few weeks with my Studer. It picked every radio station known!!

View attachment 41544

Ah not good! Wonder whether it can be resolved using some rfi blocking material inside.

tapepath · Jun 2, 2018

Hello,
I've been using the De Havilland with an Ampex 351 transport I refurbished with very satisfactory results. What appealed to me was the connection flexibility offered by the 222, I could use it with both high and low impedance playback heads, switch between NAB and IEC EQs and adjust high frequency trim to suit. I've had no problems with RF interference, the Ampex connecting cables are thoroughly shielded. I've not been in a position to compare with any other playback amps, I hope to soon be able to compare it with the original 351 electronics.
I hope this is helpful.

andromedaaudio · Jun 2, 2018

Bruce B said:
I had it for a few weeks with my Studer. It picked every radio station known!!

View attachment 41544

Lol, another question Bruce , what would be your favourite in transistor tapepres i know you like the doshi best.
Did you try the king cello , i might buy the new ballfinger transport /heads out

Audiophile Bill · Jun 2, 2018

tapepath said:
Hello,
I've been using the De Havilland with an Ampex 351 transport I refurbished with very satisfactory results. What appealed to me was the connection flexibility offered by the 222, I could use it with both high and low impedance playback heads, switch between NAB and IEC EQs and adjust high frequency trim to suit. I've had no problems with RF interference, the Ampex connecting cables are thoroughly shielded. I've not been in a position to compare with any other playback amps, I hope to soon be able to compare it with the original 351 electronics.
I hope this is helpful.

Very helpful indeed - thanks. What sort of signature would you say it has overall vs previous machines internal amps?

Audiophile Bill · Jun 2, 2018

Btw - does anyone know how it compares to King Cello? Also in the King Cello still in production?

tapepath · Jun 2, 2018

It appears the EL3501 had a solid state playback amplifier which probably means the playback head is low impedance. This is good news and bad news. The good news is that the connecting cables from the head to whatever electronics you choose doesn't have to be extremely low in capacitance. The bad news is that you will probably need 60dB of gain as opposed to 50dB with a higher output high impedance head. The way 222 accomplishes this is when used in the high gain mode is to use an opamp as the first stage of amplification and then couple this with vacuum tubes for the remaining stages. Think of using a moving coil cartridge with a solid state step up device and a tube preamp.
You might want to contact Kara Chaffee, the designer of the 222, and ask her if she has any experience with the Phillips deck.

c1ferrari · Jun 3, 2018

Audiophile Bill said:
Btw - does anyone know how it compares to King Cello? Also in the King Cello still in production?

Charles, I believe, can accomodate requests for the KC tape electronics.

Audiophile Bill · Jun 3, 2018

tapepath said:
It appears the EL3501 had a solid state playback amplifier which probably means the playback head is low impedance. This is good news and bad news. The good news is that the connecting cables from the head to whatever electronics you choose doesn't have to be extremely low in capacitance. The bad news is that you will probably need 60dB of gain as opposed to 50dB with a higher output high impedance head. The way 222 accomplishes this is when used in the high gain mode is to use an opamp as the first stage of amplification and then couple this with vacuum tubes for the remaining stages. Think of using a moving coil cartridge with a solid state step up device and a tube preamp.
You might want to contact Kara Chaffee, the designer of the 222, and ask her if she has any experience with the Phillips deck.

Hello Sir,

Actually the El3501 was both tube and solid state based. Only the later versions changed to solid state preamps. The early versions were designed for their tube based preamps indeed my friend owns the “set” - I have the early version (designed for the tube electronics).

tapepath · Jun 3, 2018

Ah, thank you for the clarification.

Brett Schuler · Dec 14, 2018

Kcin said:
I have one.

I have never compared it to a Doshi although I've heard a Doshi under show conditions. I'm still evaluating mine even though I've had it for some time. Just not enough hours on it.

View attachment 41543

Hi, what did you end up thinking of the piece once you put some hours on it?

Brett Schuler · Dec 14, 2018

Bruce B said:
I had it for a few weeks with my Studer. It picked every radio station known!!

View attachment 41544

Hi Bruce, I am considering purchasing a De Havilland for use with my A80RCmkII. Did you ever get the RF issues sorted out? If so, what did you think of it's performance?

Bruce B · Dec 14, 2018

Never got it

Brett Schuler said:
Hi Bruce, I am considering purchasing a De Havilland for use with my A80RCmkII. Did you ever get the RF issues sorted out? If so, what did you think of it's performance?

Never got the issues with the 222 sorted out. I tried the King/Cello and felt it was too noisy as well.

Had Nick build me 2 of his units and never looked back.

Brett Schuler · Dec 14, 2018

I wrote Wayne Colburn of Pass Labs yesterday as to why his phono preamps use single-ended inputs instead of balanced:

Hello Wayne,

I am hoping you can explain to me why you use single-ended inputs only on your phono stage designs. I always think of any output from a coil transducer, be it a phono cartridge, tape head, microphone coil, transformer secondary etc, as inherently balanced, center tapped or not.

I think I remember Nelson saying better noise performance is obtained with a cartridge by strapping one side of the coil to ground, am I remembering that right? Please see attached. So, diagram 1 beats digram 2 for noise, even though they are (in my mind) equivalent series circuits? Assuming the same differential pair input.

There seems to be a debate between external tape head preamplifier design guys as to which is best, with Nick Doshi firmly in the balanced camp. I was told my Studer A80RC mkII reproduce card has balanced input stage, I looked up the schematic it does not. It got me thinking as I couldn't imagine why a balanced configuration like diagram 2 or 3 wouldn't perform better.

Please clarify this for me, I would be extremely appreciative.

Kind regards,
Brett Schuler

p.s. I still have my DIY aleph 2s I built 18 years ago!

Wayne Colburn:

The single ended configuration is typically quieter by 6 dB and since noise is the biggest part of THD+noise at these levels I prefer it.
Balanced can work and I have done it but prefer single ended for phono an area I agree with Michael Fremer on. For some higher output cartridges it may be fine.
Balanced tends to be more complicated and this is the part that adds noise.
I would love to see a center tapped coil on a cartridge but was told by some cartridge makers it would be very difficult.

Kcin · Dec 14, 2018

Brett Schuler said:
Hi, what did you end up thinking of the piece once you put some hours on it?

Hi There,

I never have had any RF issues with mine it is very flexible and good construction for the price. There is always a bipolar op amp on the input regardless of low or high gain settings. I have to believe this is what I am hearing-- although the doshi uses a SS input device as well. The 222 has a cathode follower output for immunity .

There are are at least 3 others around here locally that have one. I am ok with it but in reality I like my Io Eclipse much better and have not cottoned to tape yet. Still less than 100 hrs on it though- I will run it through a burn in disc and see how it goes over the holidays.

I have heard it with a Technics 1500 series my Otari MX5050 BII , Otari MTR10 and a PR99- no big studers.

Brett Schuler · Dec 14, 2018

Kcin said:
Hi There,

I never have had any RF issues with mine it is very flexible and good construction for the price. There is always a bipolar op amp on the input regardless of low or high gain settings. I have to believe this is what I am hearing-- although the doshi uses a SS input device as well. The 222 has a cathode follower output for immunity .

There are are at least 3 others around here locally that have one. I am ok with it but in reality I like my Io Eclipse much better and have not cottoned to tape yet. Still less than 100 hrs on it though- I will run it through a burn in disc and see how it goes over the holidays.

I have heard it with a Technics 1500 series my Otari MX5050 BII , Otari MTR10 and a PR99- no big studers.

I'm not crazy about the OP amp in there. I didn't realize there was a cathode follower in there. I thought it was an OP amp feeding an Ampex 351 'inspired' 12AX7 input/eq with a discrete class A BJT output. I actually wrote Kara today asked about the topology and about using FMER heads.

The lo Eclipse is at the top of the heap for phonos but I'm still a little surprised 222 doesn't sound better given the strengths of the tape format. Interesting indeed. Thanks for sharing.

Brett Schuler · Dec 15, 2018

From Kara Chaffee, posted here with her permission:

Hi Brett,
The heads in the 10-20mH realm are too low for the 222. Most other heads are 150mH and up, which work fine. I have customers with Flux heads, but you should verify the impedance of the ER head. The 222 uses a really special bipolar op amp as a head amp --then that couples to two 12AX7s , and they are coupled to a 5687 tube cathode follower. The tube sections are fed from a 6X4 tube rectified power supply. I tried to keep as much as possible to the spirit of the Ampex 351 , but you just need more gain than the basic 12AX7 can deliver.
Sincerely,
Kara

I'm guessing the OP amp she is referring too is the Muses02, can anybody confirm this?

Kcin · Dec 15, 2018

Hi Brett,

Its not only my opinion it is the opinion of a dealer friend who has a tricked out RS1500 wired out as well. The dynamic energy is certainly more with tape than with phono- however, there is a homogeneous nature to the sound that I can't get past in every setup I have heard on his system and 2 others.

YMMV I use GFS and Atlas on the 4 point,FR64s & Brinkmann 12.1 with the Eclipse straight out with volume controls driving direct to the amp with no output transformer from the plate of the tubes to the panels. It is explosive in dynamic contrast.

I am really not sure how much a Studer would sweeten the mix... I have not heard one locally for a very long time and when I did it was an A80 version with internal electronics.

They were literally dumping A80's at the CBC ( Canadian Broadcasting Corporation) for scrap value maybe 20 years ago I was too naive about tape back then, although, I did own a Tandberg in the very late 70's that had mind of its own with funky logic controls. I just taped albums and FM back then. It was a nice deck when it worked.

I've taken to optimizing my vinyl set up and direct drive amps of late so tape is secondary . There is someone local I met a gathering that had a bottlehead- big one that ended up with the de Havilland ... not sure what that says. There is also a doshi floating around these parts. I am going to try to take a listen to that as well. At the end of the day vinyl software options are limitless and "affordable"- tape for my interest ( no classical) is limited and costly for what I hear right now.

Cripes, I could of picked up a skid's worth of Studer decks for almost freight delivery cost back then. Crazy

At the end of the day the de Havilland is very reasonably priced and very flexible. You may or may not be as sensitive to what I hear.. you need to try if you can.

De Havilland Tape Preamp

Well-Known Member

VIP/Donor

WBF Founding Member, Pro Audio Production Member

Well-Known Member

Well-Known Member

VIP/Donor

Well-Known Member

Well-Known Member

Well-Known Member

Member Sponsor & WBF Founding Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

WBF Founding Member, Pro Audio Production Member

Well-Known Member

Attachments

VIP/Donor

Well-Known Member

Well-Known Member

VIP/Donor

Similar threads